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  • 2020-2024
  • 2000-2004
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  • 1
    Digitale Medien
    Digitale Medien
    Cell populations in the lesion of human cutaneous leishmaniasis: A light microscopical, immunohistochemical and ultrastructural study (1992)
    Springer
    Virchows Archiv 421 (1992), S. 239-247 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Human cutaneous leishmaniasis ; Skin ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary To characterize the in situ cellular immune response in localized cutaneous leishmaniasis (LCL), the authors studied frozen skin biopsies from 50 patients with LCL due toLeishmania braziliensis guyanensis. A panel of 31 monoclonal antibodies was used, which defined the number and distribution of inflammatory cell subsets. Skin inflammatory infiltrates were composed of T cells (with a local CD4/CD8 ratio of 1.05±0.7 vs 1.48±0.3 in peripheral blood), macrophages and a smaller number of B cells, natural killer cells and granulocytes. Most of the T cells expressed activation markers (interleukin-2 and transferrin receptors, HLA-DR+) and an increase in T-cell-receptorγδ expression was noted. Analysis of the CD4+ subpopulations with newly available reagents showed that helper T cells (CD4+CD45RO+) exceeded the suppressor/inducer subset (CD4+CD45RA+) by 1.4∶1. There were no differences between local immune variables from patients with primary infection (45 patients) and those with recurrence (5). In 7 patients, biopsies were analysed before and 1 month after specific treatment, and did not show significant differences except for a small increase of dermal CD1a+ (Langerhans) cells/mm2. The observed pattern of cellular skin infiltration suggests an immune-mediated tissue injury including T-cell-mediated cytotoxicity and delayed hypersensitivity reactions in addition to direct parasitic action.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01611181
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  • 2
    Digitale Medien
    Digitale Medien
    The glomerular mesangium: capillary support function and its failure under experimental conditions (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. 843-856 
    Details
    ISSN: 1432-1440
    Schlagwort(e): Kidney ; Glomerulus ; Mesangium ; Mesangial failure ; Electron microscopy ; Animal models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We present a structural analysis of the ability of the biomechanical unit consisting of mesangium and glomerular basement membrane to maintain normal capillary architecture in the face of mechanical challenges due to high intraglomerular pressures. Capillary support function may be considered in terms of the stabilization of local form (development of wall tension against capillary dilation) and global form (centripetal fixation of capillary loops to maintain higher order form). The pathologic consequences of the loss of this support are illustrated by way of experimental models of mechanical mesangial failure. Such failure may express itself as mesangial widening, increased transmesangial macromolecule “traffic,” ballooning of capillary segments, and unfolding of capillary loops. Mechanisms are described by which these structural changes may lead to segmental glomerular sclerosis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00180755
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  • 3
    Digitale Medien
    Digitale Medien
    A unique case of naturally occurring mummification of human brain tissue (1992)
    Springer
    International journal of legal medicine 105 (1992), S. 173-175 
    Details
    ISSN: 1437-1596
    Schlagwort(e): Human brain tissue ; Natural mummification ; Histology ; Histochemistry ; Electron microscopy ; Elemetal analysis ; Gehirn ; Mensch ; Naturaliche Mumifikation ; Histologie ; Histochemie ; Elektronenmikroskopie ; Atmospektralanalyse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Rechtswissenschaft
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei Ausgrabungen in Bulgarien wurden Schädel und Knochen von 39 Individuen im Alter zwischen 35 und 60 Jahren, die vor ca. 45–50 Jahren begraben wurden, gefunden. Bei der nachfolgenden gerichtsmedizinischen Experitse wurden in zwei intakten Schädeln und zwischen den Knochen anderer Schädel sieben harte Gebilde (zwei ganze und fünf Fragmente), die wie geschrumpfte menschliche Gehirne aussahen, identifiziert. Entsprechende Proben von diesem Material wurden für 3–4 Tage mit 15% wässriger Lösung von Glycerol weicher gemacht und danach lichtmikroskopisch und elektronenmikroskopisch untersucht. An entsprechenden Stückchen von frischem menschlichem Gehirn und den gefundenen Proben wurde eine Atomspektral-analyse zur Bestimmung des chemischen Bestandes an Elementen durchgeführt. Die komplexe Untersuchung des Materials ergab, daß es sich bei diesem Fund um einen Sonderfall von natürlich mumifizierten menschlichen Gehirnen handelt, die durch sonderbare Bedingungen nur im Schädel der begrabenen Individuen entstanden sind.
    Notizen: Summary When skulls and bones were exhumed from a mass grave in Bulgaria and subjected to medicolegal examination they were found to originate from 39 humans aged 36–60 years old who had been buried approximately 45–50 years ago. Solid structures which strongly resembled shrunken human brain tissue were found inside 2 intact skulls. Among other bones 5 similar structures were found one of which was an almost entirely preserved human brain, and the others were fragments from different regions of the human brain. Samples of these structures were immersed in 15% aqueous glycerol solution to soften and were examined by light and electron microscopy. Sampels of this material and of fresh human brain were subjected to elementary atomic spectral analysis. These complex studies indicated the samples to be naturally mummified human brain tissue and that this process had occurred due to specific conditions within the cranial cavities after burial.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01625172
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  • 4
    Digitale Medien
    Digitale Medien
    Vascular and myofibrillar lesions in acute myoglobinuria associated with carnitine-palmityl-transferase deficiency (1992)
    Springer
    Virchows Archiv 421 (1992), S. 57-64 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Carnitine-palmityl-transferase deficiency ; Acute vascular lesions ; Acute myofibrillar lesions ; Ischaemia ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of severe exercise-induced myoglobinuria in a 14-year-old boy suffering from a carnitine-palmityl-transferase (CPT) defect is reported. Biopsies of the forearm muscle were examined using light and electron microscopy in the acute and recovery phases of the illness. The first biopsy showed the presence of scattered foci of necrosis where necrotic fibres with occasional disruptions of the basal lamina were seen around injured capillaries. Various degrees of damage and different stages of evolution were found in these foci, which also contained regenerating muscle fibres. In the second biopsy, performed 2 weeks later, most of the fibres displayed a normal structure. Necrosis was no longer present. However, in some areas perivascular fibrosis was prominent, the fibres were small and irregularly shaped, and their nuclei often centrally located. These data strongly suggest that circulatory disorders and ischaemia, brought about by premature acute metabolic imbalance, could be involved in the development of exerciseinduced myolysis observed in CPT deficiency. The risk of fibrous cardiomyopathy in these patients is pointed out.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01607140
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  • 5
    Digitale Medien
    Digitale Medien
    The pathobiology of salivary gland (1992)
    Springer
    Virchows Archiv 421 (1992), S. 105-113 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Parotid gland ; ras ; Transgenic mouse ; Electron microscopy ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In the transgenic TG.SH (mouse mammary tumour virus/v-Ha-ras) mouse, designed to develop mammary tumours, occasional spontaneous salivary gland tumours have been reported, predominantly in males. The incidence and histomorphology of salivary gland tumours in 73 TG.SH mice were surveyed and in total, 21.9% developed both overt and microscopic parotid tumours. The majority developed between 73 and 150 days of age. In 31.5% of the TG.SH mice, occasional unilateral, but more frequently bilateral exophthalmos due to hyperplasia of the intraorbital (Harderian) lacrimal gland was observed. In 70% of these animals, parotid tumours developed later. Since Harderian gland hyperplasia, occurring as early as 5 weeks of age, preceded the development of palpable salivary gland lesions, this stigma is useful for the early selection of animals likely to progress to tumour formation. Before tumour-bearing transgenic mice are considered to be suitable models of human neoplastic disease, morphological characterization is necessary to ensure that the tumours are histologically representative of the human lesions for which they are potential models. In this study, all parotid tumours consisted of acinar-like glandular structures with central lumina discernible by electron microscopy. Ultrastructurally, secretory granules evident in the apical cytoplasm of the tumour cells resembled the zymogen granules of the normal parotid acinar cell, and some cells had a prominent complement of rough endoplasmic reticulum. These features, along with focal amylase expression detected immunohistochemically in some parotid tumours, identified these neoplasms as acinic cell carcinomas that mimic the human salivary gland acinic cell carcinoma faithfully.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01607042
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  • 6
    Digitale Medien
    Digitale Medien
    Electron microscopic study of paired helical filaments and cerebral amyloid using a novel en bloc silver staining method (1992)
    Springer
    Virchows Archiv 420 (1992), S. 519-525 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Silver staining ; Paired helical filaments ; Cerebral amyloid ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A one step en bloc silver staining method which was originally established to study nucleolar organizer regions has been applied for the demonstration of both paired helical filaments (PHF) and extracellular cerebral amyloids in semi-thin sections and at the electron microscopic level. The three forms of PHF can be visualized: (1) neurofibrillary tangles are shown in all stages from first appearance in form of intracellular patches of PHF to severely degenerated shadow-like “ghost” tangles; (2) neuropil threads are distinctly stained in great numbers; and (3) PHF are easily detected as neuritic components in amyloid plaques. All forms of fibrillar extracellular amyloid structures, i.e. “diffuse”, “classical” and “burnt out” plaques, are well demonstrated; congophilic angiopathy reveals amyloid preferentially in arteries and arterioles of the leptomeninges and cortex ranging from small circumscribed patches to large circumferential amounts with occasional plaque-like condensations or broad loose accumulations of amyloid; perivascular cuffs and laminar subpial deposits of amyloid are stained as well. At the electron microscopic level all lesions are clearly visible in non uranyl/lead-stained specimens, characterized by varying numbers of silver grains on a pale background. The detailed demonstration of structures in archival material, which had been stored in paraffin and re-embedded for electron microscopy, is due to the demonstration of argyrophilic structures by the protective colloidal developer of gelatin and formic acid and to the proteolytic resistance of insoluble PHF and extracellular amyloids in plaques and congophilic angiopathy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01600257
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  • 7
    Digitale Medien
    Digitale Medien
    Malignant paraganglioma of the uterus (1992)
    Springer
    Virchows Archiv 420 (1992), S. 453-457 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Uterus ; Paraganglioma ; Intracytoplasmic hyaline globules ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We report a malignant uterine paraganglioma in a 40-year-old female, who died 7 months after the initial diagnosis. On light microscopy the tumour showed a typicalzellballen pattern as well as a pronounced cellular pleomorphism. In many tumour cells hyaline globules were demonstrated within the cytoplasm. Immunohistochemically the lesion was characterized by the presence of neuron-specific enolase, protein gene product 9.5 and synaptophysin, and electron microscopically by the occurrence of neurosecretory granules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01600518
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  • 8
    Digitale Medien
    Digitale Medien
    Occlusive microangiopathy by immunoglobulin (IgM-kappa) precipitation: pathogenetic relevance in paraneoplastic cryoglobulinemic neuropathy (1992)
    Springer
    Acta neuropathologica 83 (1992), S. 423-426 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Peripheral neuropathy ; Cryoglobulinemia ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Histological, immunohistochemical and ultrastructural sural nerve and skin biopsy findings in a case of cryoglobulinemia secondary to an IgM-kappa-producing non-Hodgkin lymphoma are described. The main finding was an occlusive microangiopathy present in both the sural nerve and the skin. Widespread cryoglobulin deposits of the proliferated vasa nervorum were associated with pronounced changes probably evoked by ischemia. Moderate perivascular inflammation, but no florid vasculitis was additionally present. Our observations indicate that occlusive microangiopathy by precipitated cryoglobulins may be a relevant pathogenetic factor in cryoglobulinemic peripheral neuropathy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00713536
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  • 9
    Digitale Medien
    Digitale Medien
    Presenile dementia with progressive supranuclear palsy tangles and Pick bodies: an unusual degenerative disorder involving the cerebral cortex, cerebral nuclei, and brain stem nuclei (1992)
    Springer
    Acta neuropathologica 84 (1992), S. 128-134 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Progressive supranuclear palsy ; Neurofibrillary tangles ; Pick body ; Immunocytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Degeneration of heterogeneous systems in the central nervous system, with widespread distribution of argyrophilic neuronal fibrillary inclusions, was found in a patient with presenile dementia. Atrophy was circumscribed in the frontal and temporal lobes. Neuronal loss was severe in the basal ganglia, subthalamic nucleus, and substantia nigra. Immunocytochemical study using anti-phosphorylated tau and anti-ubiquitin antibodies in conjunction with ultrastructural observations revealed two types of inclusions: neurofibrillary tangles (NFTs) of progressive supranuclear palsy (PSP) in the Edinger-Westphal nucleus, locus coeruleus, cerebellar dentate nucleus, inferior olivary nucleus, and posterior horn of the spinal cord; and Pick bodies (PBs) in the atrophied cerebral cortex and red nucleus. PSP-type NFTs and PBs have been demonstrated in a single case for the first time. Despite their pathognomonic significance in certain disorders, we suggest that these inclusions may reflect a form of cytoskeletal disorganization, which is not entirely restricted to a single disease entity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00311384
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  • 10
    Digitale Medien
    Digitale Medien
    Sural nerve immunoreactivity for nerve growth factor receptor in a case of localized hypertrophic neuropathy (1992)
    Springer
    Acta neuropathologica 83 (1992), S. 547-553 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Localized hypertrophic neuropathy ; Electron microscopy ; Immunohistochemistry ; Nerve growth factor receptor ; Schwann cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Immunoreactivity for nerve growth factor receptor (NGFR) was examined using a monoclonal antibody against human NGFR in the sural nerve of a 24-year-old woman, affected by localized hypertrophic neuropathy (LHN). NGFR expression was correlated with electron microscopy and with immunoreactivity for S-100 protein, laminin, HLA-DR, HNK-1, P0 glycoprotein and neurofilament peptides. Our results indicate that in LHN most of whorl-forming cells are NGFR positive and S-100 protein or HLA-DR negative. These data along with the ultrastructural features suggest their origin from perineurium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00310035
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  • 11
    Digitale Medien
    Digitale Medien
    Immunohistochemistry of cholinergic receptors (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 407-429 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Acetylcholine receptors ; Immunocytochemistry ; Electron microscopy ; Human motor endplate ; Human cerebral cortex ; Neurodegenerative disorders
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Acetylcholine and its receptors are involved in a variety of important signal transduction processes. As shown here paradigmatically for the human neuromuscular junction and the cerebral cortex, acetylcholine receptors can be visualized immunohistochemically at the cellular and subcellular level under physiological and pathological conditions. At normal motor endplates nicotinic cholinoceptors are localized at the surface of the postsynaptic junctional folds. In myasthenic syndromes investigation of muscle biopsies enables the diagnosis of receptor deficiencies at the ultrastructural level. In normal cerebral cortex pyramidal neurons are equipped with both nicotinic and muscarinic acetylcholine receptors localized to postsynaptic densities. In neuropsychiatric diseases cholinoceptor expression can be monitored at the cellular level by quantititative assessment of immunolabeled cortical neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00185457
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  • 12
    Digitale Medien
    Digitale Medien
    Ultrastructural study of ascending projections to the lateral mammillary nucleus of the rat (1992)
    Springer
    Anatomy and embryology 185 (1992), S. 547-557 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Dorsal tegmental nucleus of Gudden ; Laterodorsal tegmental nucleus ; Synaptic organization ; Anterograde tracing study ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We examined the synaptic organization of ascending projections from the pars ventralis of the dorsal tegmental nucleus of Gudden (TDV) and the laterodorsal tegmental nucleus to the lateral mammillary nucleus (LM). The LM neuropil consists of terminals containing pleomorphic synaptic vesicles and forming symmetric synaptic contact, and terminals containing round synaptic vesicles and forming asymmetric synaptic contact. They make up 63% and 37%, respectively, of all axodendritic terminals. All axosomatic terminals contain pleomorphic vesicles and make symmetric contact. Following injection of WGA-HRP into the TDV, many anterogradely labeled terminals and retrogradely labeled cells are found in the LM. Labeled terminals contact mainly proximal (more than 2 μm diameter) and intermediate (1–2 μm diameter) dendrites. Serial ultrathin sections of the LM show that 55% of axosomatic terminals are labeled anterogradely. Following injection of WGA-HRP into the laterodorsal tegmental nucleus, many anterogradely labeled terminals are found in the LM, but no retrogradely labeled cells are present. Labeled terminals contact mainly distal (less than 1 μm diameter) and intermediate dendrites as well as somata. In the LM neurons, 46% of axosomatic terminals are labeled anterogradely. All labeled terminals from these nuclei contain pleomorphic vesicles and make symmetric synaptic contact. These results indicate that almost all axosomatic terminals come from the TDV and the laterodorsal tegmental nucleus, which send inhibitory inputs to the lateral mammillary nucleus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00185614
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  • 13
    Digitale Medien
    Digitale Medien
    Neuronal autophagic vacuoles in experimental scrapie and Creutzfeldt-Jakob disease (1992)
    Springer
    Acta neuropathologica 83 (1992), S. 134-139 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Scrapie ; Creutzfeldt-Jakob disease ; Neuronal autophagy ; Neuropathology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We report the presence of autophagic vacuoles (AV) in neuronal perikarya and neuronal processes of rodents with experimental scrapie and Creutzfeldt-Jakob disease. AV were composed of sequestrated cytoplasmic areas containing ribosomes and occasionally mitochondria and small secondary vacuoles. The formation of AV may contribute to neuronal degeneration and ultimately to neuronal loss.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00308472
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  • 14
    Digitale Medien
    Digitale Medien
    Paired helical filaments in astrocytes: electron microscopy and immunohistochemistry in a case of atypical Alzheimer's disease (1992)
    Springer
    Acta neuropathologica 83 (1992), S. 228-232 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Alzheimer's disease ; Astrocytes ; Electron microscopy ; Immunohistochemistry ; Paired helical filaments
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A 54-year-old man who had cerebellar ataxia and pseudobulbar palsy at the age of 29 years, and soon developed dementia, myoclonus and convulsions, died after about 20 years in a vegetative state. Histological examination of the extensively atrophic and devastated brain (680 g) revealed the almost total loss of cerebral cortical neurons associated with numerous β-protein amyloid plaques, many extracellular tangles and a large number of hypertrophic astrocytes, and prominent amyloid angiopathy. The astrocytes were frequently immunopositive for anti-human tau antibody (anti-htau) and anti-ubiquitin antibody (anti-ubi). Double immunostaining with anti-htau and anti-glial fibrillary acidic protein (GFAP) antibody clearly demonstrated htau-positive domains within the GFAP-positive perikarya/and processes of several astrocytes. Electron microscopy of the hippocampal CA1, which was completely devoid of pyramidal neurons, revealed, in astrocytes, abnormal filaments indistinguishable from the paired helical filaments (PHFs) seen in neurons. On immunoelectron microscopy, the filaments were observed to be labeled with anti-htau and anti-ubi, exhibiting the same immunohistochemical features as neuronal PHFs. This is the first demonstration of clearly constricted and both tau- and ubiquitin-positive PHFs in astrocytes, indicating that, in some special conditions like in our case, processes similar to those that attack neurons also affect astrocytes and ultimately make the latter form PHFs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00296783
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  • 15
    Digitale Medien
    Digitale Medien
    Retinal photoreceptor fine structure in the velvet cichlid (Astronotus ocellatus) (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 363-370 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Retinal photoreceptors ; Electron microscopy ; Teleost ; Astronatus ocellatus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The structure and arrangement of the retinal photoreceptors of the velvet cichlid fish (Astronotus ocellatus) have been studied by light and electron microscopy. Rods, single cones and double (twin) cones are present. In the light-adapted state, rods are very tall cells that reach deep into the retinal epithelial (RPE) layer. The long outer segment is composed of discs of uniform diameter displaying one or two incisures. The rod inner segment shows a distal ellipsoid of mitochondria, and then narrows dramatically in the myoid region. Rod nuclei are electron dense and located deep in the outer nuclear layer. Rod synaptic spherules are small and show two to three invaginated synaptic sites as well as superficial synapses. Single cones are similar to the individual members of a double cone and all display a short tapering outer segment, a large ellipsoid of mitochondria and a myoid rich in rough endoplasmic reticulum, polysomes, Golgi zones and autophagic vacuoles. Double cones have extensive subsurface cisternae along their entire contiguous surfaces. Cone nuclei are large and vesicular and located close to or through the external limiting membrane. The synaptic pedicles of cones are larger, more electron lucent, and display more invaginated (ribbon) synapses as well as conventional (superficial) synaptic sites than do the rod spherules. Rod photoreceptors certainly undergo retinomotor movements and it is probable that cones do as well. In the light-adapted state the cone photoreceptors are arranged in a repeating square mosaic pattern with one single cone surrounded by four double (twin) cones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00185986
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  • 16
    Digitale Medien
    Digitale Medien
    Intraventricular infusion of N-methyl-D-aspartate (1992)
    Springer
    Acta neuropathologica 84 (1992), S. 630-637 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Dentrites ; Excitotoxicity ; Glutamate ; N-Methyl-d-aspartate ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This study documents the ultrastructural features of acute neuronal injury following N-methyl-d-aspartate (NMDA) receptor activation. NMDA (100 nmol/μl) or vehicle was infused over a 15-min period into the lateral ventricle of adult rats. After perfusion fixation, specimens demonstrating normal and abnormal patterns of vascular permeability to horserdish peroxidase were sampled for ultrastructural analysis. In NMDA-infused rats, brain regions exhibiting protein extravasation contained swollen dendritic profiles and abnormal neuronal perikarya. Although periventricular regions were most severely affected, parenchymal abnormalities were also detected in the cerebral cortex, septum, striatum, thalamus, hypothalamus and cerebellum. Mildly affected dendrites contained dark compact mitochondria, while in severely swollen dendrites mitochrondia were enlarged with ruptured cristae. Focal sites of plasma membrane disruption were also detected within swollen dendrites. Swollen neurons commonly displayed peripheral pallor and increased numbers of cytoplasmic vacuoles. Other neurons appeared dark and shrunken, some containing disrupted mitochrondria and pyknotic nuclei. Pretreatment with the NMDA antagonist MK-801 (2 mg/kg) attenuated the neuronal and dendritic alterations. In conditions where cerebrospinal fluid levels of glutamate are abnormally elevated, excessive NMDA receptor activation may lead to early vascular and neuronal complications which could work in concert to promote brain injury.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00227740
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  • 17
    Digitale Medien
    Digitale Medien
    Intraventricular infusion of N-methyl-d-aspartate (1992)
    Springer
    Acta neuropathologica 84 (1992), S. 621-629 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Blood-brain barrier ; Endothelium ; Excitotoxicity ; N-Methyl-d-aspartate ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The purpose of this study was to document the early cerebrovascular consequences of excessive N-methyl-d-aspartate (NMDA) receptor activation. Five microliters of NMDA (100 nmol/μl) or vehicle was infused over a 15-min period into the lateral ventricle of adult rats. The protein tracer horseradisch peroxidase (HRP) was injected intravenously for blood-brain bartier (BBB) studies. The intraventricular infusion of vehicle (n=5) caused no alterations in arterial blood pressure or microvascular damage away from the intraventicular probe tract. In contrast, NMDA infusion (n=8) led to a gradual increase in arterial blood pressure (mean 36 mm Hg). Multifocal regions of HRP extravasation were observed bilaterally throughout the neuraxis following NMDA infusion. Sites of BBB disruption and hemorrhage included brain regions bordering ventricular spaces. In addition, isolated foci of protein extravasation were commonly detected in the cerebral cortex, thalamus, basal forebrain, septum and cerebellum. Pretreatment with the noncompetitive NMDA antagonist MK-801 (2 mg/kg) substantially reduced the BBB responses to NMDA. However, microvascular abnormalities were seen in NMDA-infused rats where blood pressure elevations were inhibited by blood removal. In addition to neurons, cerebral blood vessels are also acutely affected by NMDA receptor activation. Blockage of NMDA receptor channels following brain injury may potentially provide protection by attenuating BBB breakdown and subsequent brain edema.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00227739
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  • 18
    Digitale Medien
    Digitale Medien
    Increased iron content in the putamen of patients with striatonigral degeneration (1992)
    Springer
    Acta neuropathologica 84 (1992), S. 328-330 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Striatonigral degeneration ; Putaminal pigment ; Iron ; Atomic absorption spectroscopy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We measured the total content of iron, cooper, zinc and manganese in the putamen of four patients with striatonigral degeneration (SND) and age-and gender-matched normal controls. The iron content in the SND patients was five times greater than in the controls. Electron microscopic histochemistry revealed the iron reaction products in the pigments showing a triphasic pattern of coarse, electron-dense globules, fine granular and fibrillary materials, and lamellated structures. These findings suggest that increased iron deposition may be related to pigment formation in the putament of SND.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00227827
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  • 19
    Digitale Medien
    Digitale Medien
    Cerebral granular cell tumors: report of a case and a note on their nature and expected behavior (1992)
    Springer
    Acta neuropathologica 84 (1992), S. 680-685 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Histiocytic markers ; Astrocytoma ; Electron microscopy ; Glial fibrillary acidic protein ; Granular cell tumor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of cerebral granular cell tumor (GCT) is reported. Histologically, the growth was composed of benign astrocytes, granular cells and transitional forms between both elements. Glial fibrillary acidic protein was detected in the glial component and, to a lesser extent, in the granular cells. Alpha-1-antichymotrypsin was demonstrated in the latter component only. Ultrastructural study also supported the evidence that neoplastic astrocytes became granular cells. The survey of the literature and our own results suggest that GCTs in this particular location, even when histologically benign, seem to have a worse prognosis than the low-grade supratentorial astrocytomas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00227746
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  • 20
    Digitale Medien
    Digitale Medien
    Retinal pigment epithelial fine structure in the velvet cichlid (Astronotus ocellatus) (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 371-377 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Retinal pigment epithelium (RPE) ; Electron microscopy ; Teleost ; Astronatus ocellatus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The morphology of the retinal pigment epithelium (RPE), choriocapillaris and Bruch's membrane (complexus basalis) have been studied by light and electron microscopy in the velvet cichlid (Astronotus ocellatus). The RPE is composed of a single layer of large columnar cells. The basal (scleral) border of these cells is minimally infolded, whereas the apical (vitreal) surface displays numerous pigment-laden processes which in light-adaptation surround both rod and cone outer segments. Laterally the RPE cells are joined by a series of basally located tight junctions. Wandering phagocytes are a constant feature within this epithelial membrane. The RPE cells display a large, vesicular nucleus, numerous mitochondria, much smooth endoplasmic reticulum, polysomes, myeloid bodies, phagosomes and melanosomes. Rough endoplasmic reticulum is relatively scarce within these cells. Although only light-adapted specimens were examined, it is thought that the melanosomes are capable of extensive retinomotor movement. The endothelium of the choriocapillaris facing Bruch's membrane is typically very thin but shows few fenestrations. Bruch's membrane is typical of other teleost species in that it is composed of only three layers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00185987
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  • 21
    Digitale Medien
    Digitale Medien
    The cellular network of interstitial cells associated with the deep muscular plexus of the guinea pig small intestine (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 519-527 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Intestine ; Interstitial cells ; Innervation ; Electron microscopy ; Guinea pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Systematic examination using electron microscopic montages and serial sections has demonstrated that three types of interstitial cell, namely gap junction-rich cells, glycogen-rich cells and fibroblast-like cells, are densely located along the whole extent of the deep muscular plexus of the guinea pig small intestine. They tend to be distributed in an alternating fashion in the cellular network, connected with muscle cells of the outer, circular layer by means of gap junctions. These three types of interstitial cell show close relations to two types of nerve varicosity: one type is characterized by clear round vesicles with diameters of about 50 nm, and the other by flattened vesicles measuring about 35 nm by 70 nm. Electron-dense patches have been observed at the cytoplasmic side of the axonal membranes. Muscle cells of both inner and outer circular layers also show close relations to these two types of nerve varicosity. These morphological features are discussed with the implication that they may have some regulatory role in intestinal movement.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00186974
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  • 22
    Digitale Medien
    Digitale Medien
    Effects of cepharanthine and minoxidil on proliferation, differentiation and keratinization of cultured cells from the murine hair apparatus (1992)
    Springer
    Archives of dermatological research 284 (1992), S. 290-296 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Cepharanthine ; Minoxidil ; Culture ; Hair cells ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effects of cepharanthine and minoxidil on proliferation, differentiation and keratinization of cultured cells from the murine hair apparatus were examined electron microscopically. Both cepharanthine and minoxidil stimulated cell proliferation and delayed initiation of differentiation and keratinization of the cultured cells. On day 6, most control cells (87%) cultured in a 0.03 mM calcium medium without cepharanthine and minoxidil were differentiated into several subpopulations corresponding to those of in vivo cell layers of the hair apparatus, while most of the cells cultured with cepharanthine (71%) or minoxidil (70%) were still immature. On day 13, the number of degenerated cells increased (63%) in the control culture, whereas in the culture treated with cepharanthine or minoxidil, cell degeneration scarcely occurred (5% and 8%, respectively). Differentiated cells having tonofilaments were often observed in the cepharanthine- and minoxidil-treated cultures (76% and 72%, respectively). Elevation of extracellular calcium up to 1.0 mM induced keratinization (34%) in the control culture on day 6, while no keratinized cells were observed in the cepharanthine- or minoxidil-treated culture. On day 13 keratinization similarly occurred in the cultures with cepharanthine (30%) or minoxidil (48%). These results show that both cepharanthine and minoxidil may directly influence proliferation, differentiation and keratinization of cultured cells from the hair apparatus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00372583
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  • 23
    Digitale Medien
    Digitale Medien
    Ultrastructural localization of actin in normal human skin (1992)
    Springer
    Archives of dermatological research 284 (1992), S. 242-245 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Immunogold ; Electron microscopy ; Human skin ; Actin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Normal human skin was embedded in Lowicryl K4M. Actin microfilaments were localized by applyinga postembedding immunogold technique using the monoclonal anti-actin antibody HHF35. Actin microfilaments are part of the cytoskeleton in muscle and nonmuscle cells. Together with myosin they produce contraction. The antibody labelled myofilaments in smooth muscle arrector pili cells, myoepithelial cells and pericytes. In sweat gland cells the microvilli system, a zone beneath the cytoplasma membrane correponding to the adhesion belt region, and apocrine decapitation formations showed labelling.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00375802
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  • 24
    Digitale Medien
    Digitale Medien
    Basal lamina-like material and hemidesmosome-like structures associated with dermal papilla cells in the normal human anagen hair follicle (1992)
    Springer
    Archives of dermatological research 284 (1992), S. 303-306 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Hair follicle ; Basal lamina ; Dermal papilla cells ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00372585
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  • 25
    Digitale Medien
    Digitale Medien
    Electron-microscopic description of accretions occurring on tips of infected and non-infected central venous catheters (1992)
    Springer
    Intensive care medicine 18 (1992), S. 464-468 
    Details
    ISSN: 1432-1238
    Schlagwort(e): Catheter ; Electron microscopy ; Infection ; Adherence ; Candida albicans
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Objective The purpose of the study was do describe the architecture of accretions occurring on the tips of central venous catheters (CVC). Design A conservative procedure was used followed by two different techniques of electron microscopy Setting and patients the study included 19 catheters which have been used on intensive cared adults, and which were chosen among those of parallel 300 CVC study. Measurements and results CVC were considered sterile, contaminated, colonized or infected according to microbiological and clinical criteria. CVC were found to remain much cleaner than in past clescriptions. When present, accretions were located on the olive-shaped end, and displayed stratified structures with three types of material: amorphous material, thrombus components and inflammatory cells. Bacteria were not seen, even on culture positive CVC. Candida albicans was found on one CVC in the cytoplasm of ganulocytes, and made xio direct contact with the plastic surface. Conclusion This technique should contribute to the understanding of the pathobiology of CVC infection and provide information proving or precluding the involvement of microbial adherence to polymers in vivo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01708582
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  • 26
    Digitale Medien
    Digitale Medien
    Calcium binding protein (calbindin D28k) immunoreactivity in the hamster superior colliculus: ultrastructure and lack of co-localization with GABA (1992)
    Springer
    Experimental brain research 89 (1992), S. 115-124 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Immunocytochemistry ; Visual pathways ; Electron microscopy ; Hamster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The expression of specific calcium binding proteins is being used increasingly as a potential neuroanatomical marker for neurons with similar functions. In this study, the distribution of calbindin D28k in the superior colliculus (SC) of adult hamsters was examined by light and electron microscopy. Calbindin immunoreactivity was prominent in specific regions and laminae of the SC throughout its rostrocaudal extent, and was found to label horizontal, vertical and stellate cell types. In addition, calbindin label highlighted “bridges” of neuronal processes in the intermediate layers. The most frequent calbindin-immunoreactive profiles seen in the electron microscope were dendrites, some of which were post-synaptic to apparent retinal ganglion cell axon terminals. Labelled axons and axon terminals were less frequently encountered. There was considerable overlap between the size distribution of calbindin D28k-immunoreactive neurons and that of GABA-immunoreactive or Nissl stained neurons in the SC. However, using a double fluorescent labelling technique, and examination of the tissue with confocal laser microscopy, no neurons were observed in the hamster SC that showed immunoreactivity for both calbindin and GABA. In this regard, the SC is similar to the mammalian lateral geniculate nucleus and the pretectum, but differs from the neocortex, where calbindin and GABA are colocalized. The demonstration in the SC, as well as other parts of the nervous system, of sub-populations of neurons that contain distinct calcium-binding proteins suggests that these neurons have different functional properties. Correlative studies may clarify the relevance of these cytoplasmic components as cell markers, as well as their different patterns of association with neurotransmitters and peptides.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00229008
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  • 27
    Digitale Medien
    Digitale Medien
    High-pressure freezing of soybean nodules leads to an improved preservation of ultrastructure (1992)
    Springer
    Planta 188 (1992), S. 155-163 
    Details
    ISSN: 1432-2048
    Schlagwort(e): Bradyrhizobium ; Electron microscopy ; Glycine (root nodules) ; High-pressure freezing ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract High-pressure freezing of chemically untreated nodules of soybean (Glycine max (L.) Merr.), in sharp contrast to chemical fixation and prefixation, appears to preserve the ultrastructure close to the native state. This is supported by the observation that the peribacteroid membrane of high-pressure-frozen samples is tightly wrapped around the bacteroids, a finding that is fully consistent with the current views on the physiology of oxygen and metabolite transport between plant cytosol and bacteroids. In soybean root nodules, the plant tissue and the enclosed bacteria are so dissimilar that conventional aldehyde-fixation procedures are unable to preserve the overall native ultrastructure. This was demonstrated by high-pressure freezing of nodules that had been pre-fixed in glutaraldehyde at various buffer molalities: no buffer strength tested preserved all ultrastructural aspects that could be seen after high-pressure freezing of chemically untreated nodules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216809
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  • 28
    Digitale Medien
    Digitale Medien
    Studies on the hepatotoxicity induced by bis (tributyltin) oxide (1992)
    Springer
    Archives of toxicology 66 (1992), S. 182-187 
    Details
    ISSN: 1432-0738
    Schlagwort(e): Bis(tributyltin) oxide ; Liver ; Electron microscopy ; X-ray microanalysis ; Biochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The toxic effects of bis (tributyltin) oxide (TBTO) on the rat liver were studied with an electron microscope and the accumulation sites of tin were determined with an X-ray microanalyzer. The activities of serum enzymes and the concentration of serum bilirubin were also analyzed. Male Wistar rats received an intramuscular injection of 0.5 ml/kg of TBTO. Marked swelling of the mitochondria appeared in the hepatocytes 4 h after injection of TBTO. Cytoplasmic vacuoles, which contained degenerated mitochondria, gradually increased in number in these hepatocytes. This in turn may have caused a decrease in the volume of hepatic cell cords and an enlargement of sinusoids in the entire hepatic lobule. However, fine structures of intrahepatic bile ducts were not altered. By X-ray microanalysis, tin peaks were preferentially obtained from swollen mitochondria of the hepatocytes. By polarographic analysis of the respiratory responses of mitochondria, it was demonstrated that rates of state 4 respiration and respiratory control ratio were significantly disturbed in TBTO-treated rats in comparison with those of controls. The activities of AST (aspartate aminotransferase) and ALT (alanine aminotransferase) were significantly increased after TBTO treatment, but those of ALP (alkaline phosphatase), LAP (leucine aminopeptidase) and total bilirubin were not changed. These results indicated that parenterally administered TBTO accumulated in the liver cell mitochondria and disturbed oxidative phosphorylation. Mitochondrial dysfunction might induce severe damage of the hepatocytes. Four days after injection of TBTO, hepatic structures and chemical indices were almost restored by the regeneration of hepatocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01974012
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  • 29
    Digitale Medien
    Digitale Medien
    Dynamics of PhiX174 protein E-mediated lysis of Escherichia coli (1992)
    Springer
    Archives of microbiology 157 (1992), S. 381-388 
    Details
    ISSN: 1432-072X
    Schlagwort(e): PhiX174 ; Bacterial lysis ; Escherichia coli ; Electron microscopy ; Membranes ; Cell envelope
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Expression of cloned gene E of bacteriophage PhiX174 induces lysis by formation of a transmembrane tunnel structure in the cell envelope of Escherichia coli. Ultrastructural studies of the location of the lysis tunnel indicate that it is preferentially located at the septum or at polar regions of the cell. Furthermore, the diameter and shape of individual tunnel structures vary greatly indicating that its structure is not rigid. Apparently, the contours of individual lysis tunnels are determined by enlarged meshes in the peptidoglycan net and the force produced at its orifice, by the outflow of cytoplasmic content. Once the tunnel is formed the driving force for the lysis process is the osmotic pressure difference between cytoplasm and medium. During the lysis process areas of the cytoplasmic membrane which are not tightly attached to the envelope are extended inward by the negative pressure produced during lysis. After cell lysis external medium can diffuse through the lysis tunnel filling the inner cell space of the still rigid bacterial ghosts.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00248685
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  • 30
    Digitale Medien
    Digitale Medien
    Age-related immunoreactivity pattern in medulloblastoma (1992)
    Springer
    Child's nervous system 8 (1992), S. 326-331 
    Details
    ISSN: 1433-0350
    Schlagwort(e): Medulloblastomas ; Immunohistochemistry ; Cytokeratins ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Thirty-five paraffin-embedded medulloblastomas (19 from children and 16 from adults; 24 classic medulloblastomas, 10 desmoplastic medulloblastomas, 1 tumor with neuronal differentiation) were examined for reactions with antibodies against glial fibrillary acidic protein (GFAP), cytokeratins KL1 and MNF116, desmin, and vimentin. Only the tumor from the youngest patient, a 152-day-old boy, showed a positive immunoreaction for cytokeratins. Because of this age-related expression of cytokeratins in medulloblastomas primarily in very young children, cytokeratin positivity was interpreted as a sign of tumor immaturity. Five medulloblastomas showed scattered GFAP-positive reactive astrocytes and/or other positive, probably neoplastic, cells. Only two tumors showed GFAP immunoreactivity in unequivocally neoplastic cells. Of six tumors that reacted with vimentin, three showed strong reactivity throughout, one being the tumor from the 152-day-old boy. The remaining three demonstrated nests of vimentin-positive cells with weak or intense somatic immunoreactivity for vimentin. None of the 35 cases showed positivity for desmin, indicating that mesenchymal differentiation is restricted to the rare so-called medullomyoblastomas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00296563
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  • 31
    Digitale Medien
    Digitale Medien
    The human placental transferrin receptor: Reconstitution into liposomes and electron microscopy (1992)
    Springer
    Bioscience reports 12 (1992), S. 471-482 
    Details
    ISSN: 1573-4935
    Schlagwort(e): Transferrin ; Receptor ; Isolation ; Reconstitution ; Liposomes ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Human transferrin receptor was isolated from Triton X-100 solubilized placental plasma membranes by a rapid one-step chromatographic procedure based on immunoadsorption of the receptortransferrin complex on anti-transferrin Sepharose and lectin-affinity on wheat germ agglutinin. Following exchange of Triton X-100 with CHAPS or n-octylglucoside, the purified receptor was incorporated into egg phosphatidylcholine liposomes upon, detergent removal by dialysis (lipid/protein ratio 15:1 to 45:1 (w/w) Reconstitution of the receptor was confirmed by trypsin cleavage to dissociate the large extracellular receptor domain from the liposomal membranes. Electron micrographs of the receptor-lipid recombinants negatively stained with sodium sillicotungstate, showed ographs of the receptor-lipid recombinants negatively stained with sodium sillicotungstate, showed that the receptor molecules distributed very inhomogeneously on the liposomes, most receptors being clustered. Single copies of the receptor were seen as elongate structures (5×10 nm) oriented with their long axis parallel to the liposome surface and separated from this by a 2–3 nm gap. This result provides evidence for a narrow connecting link between the globular extracellular receptor domain and the membrane spanning segment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01122035
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  • 32
    Digitale Medien
    Digitale Medien
    Exo-endocytosis in isolated peptidergic nerve terminals occurs in the sub-second range (1992)
    Springer
    Bioscience reports 12 (1992), S. 495-501 
    Details
    ISSN: 1573-4935
    Schlagwort(e): Electron microscopy ; secretion ; neuropeptides ; exocytosis ; endocytosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Exo- and endocytotic processes induced by depolarization of isolated neurosecretory nerve terminals show a close temporal correlation, which suggests a short time of integration of the neurosecretory granule membrane with the plasma membrane. In order to determine minimal time requirements for exocytosis-coupled endocytosis to occur, we have analyzed by electron microscopy uptake of horserdish peroxidase (HRP) as a fluid phase marker at the onset of depolarization. We have applied rapid mixing and sampling (quenched flow) to assess events in subsecond time peroids after stimulation. A significant number of labelled endocytotic vacuoles was observed during the first second of depolarization. This number then further increased by a factor of about 2 (within 5 s) and 4 (within 50s). Thus, as for exocytosis, the rate of endocytosis decreased considerably during prolonged stimulation. These data indicate i) that a substantial proportion of secretory granules undergoes exocytosis very shortly after stimulation, and ii) that, following exocytosis, the minimal time required for consecutive membrane retrieval is in the sub-second range.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01122037
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  • 33
    Digitale Medien
    Digitale Medien
    Effect of haloperidol and clozapine on the density of “perforated” synapses in caudate, nucleus accumbens, and medial prefrontal cortex (1992)
    Springer
    Psychopharmacology 106 (1992), S. 45-52 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Haloperidol ; Clozapine ; Perforated synapses ; Electron microscopy ; Tardive dyskinesia ; Extrapyramidal syndrome
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Perforated synapses, which contain a discontinuous density along the postsynaptic membrane, can increase or decrease in numbers following various behavioral and biochemical manipulations. We have previously established that 14-day treatment with haloperidol causes an increase in the number of perforated synapses within the caudate nucleus (dorsolateral region) but not the nucleus accumbens (Meshul and Casey 1989). This effect was reversed if the animals were withdrawn from the drug for an equivalent period of time. We have now further examined the effects of haloperidol administration, which is associated with a high incidence of extrapyramidal side effects (EPS) and tardive dyskinesia (TD), and assessed the effects of clozapine, which appears to have a lower potential for inducing EPS and TD. Administration of haloperidol for 2 weeks significantly increased the percentage of perforated synapses in the caudate, but not in the nucleus accumbens or layer VI of medial prefrontal cortex (MPCx). There was an increase in specific [125I]epidepride binding to D-2 receptors in the caudate nucleus and MPCx following haloperidol. Administration of clozapine for 2 weeks did not affect the percentage of perforated synapses in any of the three dopamine (DA)-rich regions that were examined. There was an increase in specific [3H]SCH 23390 binding to D-1 receptors and in specific [125I]epidepride binding to D-2 receptors only within MPCx following clozapine. The absence of any change in the density of perforated synapses within the dorsolateral caudate nucleus following clozapine correlates with: 1) the lack of effect on specific DA receptor binding or down regulation of serotonin (5-HT2) receptors (as reported by others), or 2) the inability in clozapine-treated animals to depolarize block substantia nigra (A9) DA neurons. These results may be related to the low incidence of EPS and TD observed with clozapine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02253587
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  • 34
    Digitale Medien
    Digitale Medien
    The metathoracic wing-hinge chordotonal organ of an atympanate moth, Actias luna (Lepidoptera, Saturniidae): a light- and electron-microscopic study (1992)
    Springer
    Cell & tissue research 267 (1992), S. 455-471 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Chordotonal organ ; Scolopidium ; Homology ; Electron microscopy ; Sensilla ; Evolution ; Actias luna (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The structure of a simple chordotonal organ, the presumed homologue of the noctuoid moth tympanal organ, is described in the atympanate moth, Actias luna. The organ consists of a proximal scolopidial region and a distal strand, which attaches peripherally to the membranous cuticle ventral to the hindwing alula. The strand is composed of elongate, microtubule-rich cells encased in an extracellular connective tissue sheath. The scolopidial region houses three mononematic, monodynal scolopidia, each comprised of a sensory cell, scolopale cell, and attachment cell. The dendritic apex is octagonally shaped in transverse section, its inner membrane lined by a laminated structure reminiscent of the noctuoid tympanal organ ‘collar’. A 9+0-type cilium emerges from the dendritic apex, passes through both the scolopale lumen and cap, and terminates in an extracellular space distal to the latter. Proximal extensions of the attachment cell and distal prolongations of the scolopale cell surrounding the cap are joined by an elaborate desmosome, with which is associated an extensive electron-dense fibrillar plaque. Within the scolopale cell, this plaque constitutes the scolopale ‘rod’ material. The data are discussed in terms of both the organ's potential function, and its significance as the evolutionary proto-type of the noctuoid moth ear.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319368
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  • 35
    Digitale Medien
    Digitale Medien
    Synaptic contacts of tyrosine hydroxylase-immunoreactive elements in the inner plexiform layer of the retina of Bufo marinus (1992)
    Springer
    Cell & tissue research 267 (1992), S. 525-534 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Retina ; Dopaminergic neurons ; Synapses ; Inner plexiform layer ; Immunocytochemistry ; Electron microscopy ; Bufo marinus (Anura)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Tyrosine hydroxylase (TH) immunocytochemistry was utilized to quantify dopaminergic synapses in the inner plexiform layer of the retina of Bufo marinus. Since dopaminergic cells have bistratified dendritic arborisation in the inner plexiform layer, attention was given to the segregation of synapses between the scleral and the vitreal sublaminae. Light-microscopically, a more elaborate dendritic branching was observed in the scleral than in the vitreal sublamina. In contrast, about 55% of synapses occurred in the vitreal one fifth of the inner plexiform layer, 30% in the scleral fifth, and 15% in the intermediate laminae. Input sources and output targets showed only minor quantitative differences between sublaminae 1 and 5. TH-immunoreactive processes were found in presynaptic (62.8%) and postsynaptic (37.2%) positions. Synapses to the stained dendrites derived from bipolar (40.4%) and amacrine (59.6%) cells, whereas outputs from the TH-positive processes were directed to amacrine cells (56.8%) and to small and medium-sized dendrites (35.4%); at least some of these can be considered as ganglion cell dendrites. TH-positive profiles neither formed synapses with each other nor were presynaptic to bipolar cell terminals. Junctional appositions of the immunoreactive profiles were occasionally seen on non-stained amacrine and ganglion cell dendrites in the scleral sublamina of the inner plexiform layer and on optic axons in the optic fibre layer. Although dopaminergic cells are mainly involved in amacrine-amacrine interactions, inputs from bipolar terminals and outputs to ganglion cell dendrites were also substantial, suggestive of a role also in vertical information processing.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00319375
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  • 36
    Digitale Medien
    Digitale Medien
    Cellular differences in the regeneration of murine skeletal muscle: a quantitative histological study in SJL/J and BALB/c mice (1992)
    Springer
    Cell & tissue research 269 (1992), S. 159-166 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Regeneration ; Skeletal muscle ; Injury ; Autoradiography ; Morphometry ; Electron microscopy ; Mouse (SJL/J BALB/c)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Skeletal muscle regeneration in SJL/J and BALB/c mice subjected to identical crush injuries is markedly different: in SJL/J mice myotubes almost completely replace damaged myofibres, whereas BALB/c mice develop fibrotic scar tissue and few myotubes. To determine the cellular changes which contribute to these differential responses to injury, samples of crushed tibialis anterior muscles taken from SJL/J and BALB/c mice between 1 and 10 days after injury were analysed by light and electron microscopy, and by autoradiography. Longitudinal muscle sections revealed about a 2-fold greater total mononuclear cell density in SJL/J than BALB/c mice at 2 to 3 days after injury. Electron micrographs identified a similar proportion of cell types at 3 days after injury. Autoradiographic studies showed that the proportions of replicating mononuclear cells in both strains were similar: therefore greater absolute numbers of cells (including muscle precursors and macrophages) were proliferating in SJL/J muscle. Removal of necrotic muscle debris in SJL/J mice was rapid and extensive, and by 6 to 8 days multinucleated myotubes occupied a large part of the lesion. By contrast, phagocytosis was less effective in BALB/c mice, myotube formation was minimal, and fibrotic tissue conspicuous. These data indicate that the increased mononuclear cell density, more efficient removal of necrotic muscle, together with a greater capacity for myotube formation in SJL/J mice, contribute to the more successful muscle regeneration seen after injury.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00384736
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  • 37
    Digitale Medien
    Digitale Medien
    Differential localization of leu-enkephalin and hyperglycemic hormone in axon terminals of the sinus gland of the crabsCarcinus maenas, eriocheir sinensis, andUca pugilator (1992)
    Springer
    Cell & tissue research 270 (1992), S. 521-526 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Enkephalins ; Neuropeptides ; Neurohemal organ ; Immunogold ; Electron microscopy ; Carcinus maenas, Uca pugilator, Eriocheir sinensis (Crustacea)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Leu-enkephalin containing secretory granules were demonstrated in axon terminals of immunogoldlabeled electron-microscopic sections of the sinus gland of three brachyuran crustaceans. These granules have a diameter of 120+-15 nm and differ in electron density from those located in adjacent terminals containing hyperglycemic or molt-inhibiting hormone. These neurohormones do not show co-localization with leu-enkephalin. The cross-reactivity of leu-enkephalin antiserum with met-enkephalin is less than 1%. The sinus glands of the three species examined show no immunoreactivity for FMRF-amide. A modulatory activity of endogenous enkephalin by paracrine mechanisms is suggested.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00645054
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  • 38
    Digitale Medien
    Digitale Medien
    Immuno-electron-microscopic localization of basic fibroblast growth factor in the dystrophic mdx mouse masseter muscle (1992)
    Springer
    Cell & tissue research 270 (1992), S. 569-576 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Basic fibroblast growth factor ; Regeneration ; Degeneration ; Immunohistochemistry ; Electron microscopy ; Masseter muscle ; Myoneural junction ; Mouse (dystrophic mdx)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The localization of basic fibroblast growth factor (bFGF)-like immunoreactivity in the masseter muscle of dystrophic mdx mice on postnatal day 28 was investigated by immunoblot analysis and electron microscopy. Crude homogenate of the masseter muscle, when subjected to immunoblotting with a bFGF antiserum, exhibited a main band with the same molecular weight (18 kDa) as bovine bFGF. By electron microscopy, bFGF immunoreactivity was detected in small regenerating myocytes; the smaller cells were the premature myocytes, the most intense staining was the immunoreactivity within the cytoplasm. Putative precursors of the muscle cells with a few myofilaments, which were most intensely labeled with anti-bFGF, contacted each other and possibly developed into multinucleated myocytes through cell fusion. Mature myocytes with densely packed myofilaments and peripherally located nuclei did not exhibit bFGF immunoreactivity; they formed myoneural junctions with motor nerve endings immunoreactive for bFGF. Early differentiating myocytes with intense bFGF-like immunoreactivity did not make contact with immunoreactive nerve terminals. Degenerating large myocytes with a limited number of distorted and/or disrupted myofilaments exhibited electron-dense deposits in the cristae of mitochondria; these deposits were not abolished by immunoadsorption control experiments. Thus, the cell-size-dependent decrease in bFGF immunoreactivity in regenerating but not in degenerating myocytes provides a morphological basis for an autoregulatory role of bFGF in muscle regeneration. This study suggests that neuronal bFGF is not involved in initial muscle regeneration in the dystrophic mdx mouse.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00645060
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  • 39
    Digitale Medien
    Digitale Medien
    Ovarian innervation develops before initiation of folliculogenesis in the rat (1992)
    Springer
    Cell & tissue research 270 (1992), S. 87-93 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ovarian nerves ; Development ; Folliculogenesis ; Tyrosine hydroxylase ; Immunohistochemistry ; Electron microscopy ; Rat (Sprague Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Sympathetic neurotransmitters have been shown to be present in the ovary of the rat during early postnatal development and to affect steroidogenesis before the ovary becomes responsive to gonadotropins, and before the first primordial follicles are formed. This study was undertaken to determine if development of the ovarian innervation is an event that antedates the initiation of folliculogenesis in the rat, Rattus norvegicus. Serial sections of postnatal ovaries revealed a negligible frequency of follicles 24 h after birth (about 1 primordial follicle per ovary). Twelve hours later there were about 500 follicles per ovary, a number that more than doubled to about 1300 during the subsequent 12 h, indicating that an explosive period of follicular differentiation occurs between the end of postnatal days 1 and 2. Electron microscopy demonstrated that before birth the ovaries are already innervated by fibers containing clear and dense-core vesicles. Immunohistochemistry performed on either fetal (day 19) or newborn (less than 15h after birth) ovaries showed the presence of catecholaminergic nerves, identified by their content of immunoreactive tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis. While some of these fibers innervate blood vessels, others are associated with primordial ovarian cells, thereby suggesting their participation in non-vascular functions. Since prefollicular ovaries are insensitive to gonadotropins, the results suggest that the developing ovary becomes subjected to direct neurogenic influences before it acquires responsiveness to gonadotropins.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00381883
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  • 40
    Digitale Medien
    Digitale Medien
    The effects of ageing on the morphology and function of the zonae fasciculata and reticularis of the rat adrenal cortex (1992)
    Springer
    Cell & tissue research 270 (1992), S. 265-272 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal cortex ; Ageing ; Steroidogenesis ; Electron microscopy ; Morphometry ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The morphological counterpart of the well-known age-dependent marked impairment of glucocorticoid secretion of rat adrenals was investigated by use of morphometric techniques. For this purpose 4-, 8-, 16- and 24-month-old rats were studied. Despite the notable lowering of both basal and ACTH-stimulated production of corticosterone by collagenase-dispersed inner adrenocortical cells, ACTH and corticosterone plasma concentrations displayed significant increases with ageing. Zona fasciculata (ZF) and zona reticularis (ZR) showed a notable hypertrophy in aged rats, which was due to rises in both the average volume and number of their parenchymal cells. The hypertrophy of ZF and ZR cells was in turn associated with increase in the volume of the mitochondrial compartment and proliferation of smooth endoplasmic reticulum, i.e., the two organelles involved in steroid-hormone synthesis. All these morphologic changes, conceivably due to the chronic exposure to high levels of circulating ACTH, are interpreted as a response enabling ZF and ZR to compensate for their age-dependent lowering in glucocorticoid secretion. Stereology also demonstrated that ZF and ZR cells underwent a striking age-related lipid-droplet repletion. Lipid droplets are the intracellular stores of cholesterol esters, the obligate precursors of steroid hormones in rats. This finding is in keeping with the contention that the mechanism underlying the age-dependent decline in rat-adrenal glucocorticoid secretion mainly involves impairments of the utilization of intracellular cholesterol previous to its intramitochondrial transformation to pregnenolone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00328012
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  • 41
    Digitale Medien
    Digitale Medien
    Characterization of macrophage-like cells in the external layers of human small and large intestine (1992)
    Springer
    Cell & tissue research 270 (1992), S. 273-279 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Macrophages ; Small intestine ; Large intestine ; External muscle layer ; Immunohistochemistry ; Histochemistry ; Electron microscopy ; Man
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the external layers of human small and large intestine macrophage-like cells were characterized by immunohistochemical, histochemical and electronmicroscopical methods. Using immunohistochemistry and a number of monoclonal antibodies, the presence and distribution of phenotypic subpopulations of macrophages were evaluated. In all locations macrophage-like cells were identified with antibody EBM11, which recognizes CD68 antigen, C3bi which recognizes CD11b, and partly with an antibody which recognizes protein 150,95 (CD11c). Macrophage-like cells in the external muscle layer were HLA-DR-positive (expressing the MHC class-II antigen), in contrast to macrophage-like cells in the subserosa and submucosa. Macrophage-like cells in the external muscle layer were mostly acid phosphatase-negative, and at the electron-microscopic level they were found to have features of macrophages: primary lysosomes, coated vesicles and pits. However, very few secondary lysosomes were present. Birbeck granules were not observed. It is concluded that in the external muscle layer of human small and large intestine numerous macrophages of a special type are present. It is discussed whether this cell type plays a role in gastrointestinal motility and/or has an immunological function.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00328013
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  • 42
    Digitale Medien
    Digitale Medien
    Initial formation of cellular intrinsic fiber cementum in developing human teeth (1992)
    Springer
    Cell & tissue research 267 (1992), S. 321-335 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Teeth ; Cementum ; Cementoblasts ; Matrix production ; Electron microscopy ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present study describes the formative process of the initiation of cellular intrinsic fiber cementum (CIFC) in still growing human teeth. From 29 premolars and molars with incomplete roots developed to 60–90% of their final length, 8 premolars (with roots formed to three quarters of their final length) were selected for electron-microscopic investigation. All teeth were clinically intact and prefixed in Karnovsky's fixative immediately after extraction. Most of them were decalcified in ethylene diaminetetraacetic acid (EDTA), and the apical part of the roots was divided axially into mesial and distal portions that were subdivided in about 5 slices each. Following osmication and embedding in Epon, these blocks were cut for light- and electron-microscopic examination. In addition, 5 teeth with incomplete roots were freed from organic material and processed for scanning electron microscopy. It was found that CIFC-initiation commenced very close to the advancing root edge and resulted in a rapid cementum thickening. Thereafter, appositional growth continued on the already established cementum surface. Large, basophilic and rough endoplasmic reticulum-rich cementoblasts, some of which became cementocytes, were responsible for both fast and slow CIFC-formation. The CIFC-matrix was free of Sharpey's fibers and composed of more or less organized intrinsic collagen fibrils, in part fibril bundles, that ran roughly parallel to the root surface. Initially, the cementum fibrils intermingled with those of the dentinal collagen fibrils, which were not yet mineralized. This boundary subsequently underwent calcification. The development of collagen fibril bundles and their extracellular arrangement were associated with cytoplasmic processes probably involved in fibril formation and fibril assembly. Many cementoblasts contained intracytoplasmic, membrane-bounded collagen fibrils, which probably were related to fibril formation rather than degradation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00302971
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  • 43
    Digitale Medien
    Digitale Medien
    Development of cytoplasmic digitations between Leydig cells and testicular macrophages of the rat (1992)
    Springer
    Cell & tissue research 267 (1992), S. 385-389 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Leydig cells ; Macrophages ; Development, ontogenic ; Electron microscopy ; Testis ; (Rat Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Testicular macrophages and Leydig cells from adult animals are known to be functionally coupled. For example, secreted products from macrophages stimulate testosterone secretion by Leydig cells. In adult rat testes, structural coupling also exists between these cells. This coupling consists of cytoplasmic projections from Leydig cells located within cytoplasmic invaginations of macrophages. Although macrophages are known to exist in the testis in immature animals, it is not known when these digitations develop. The purpose of the present study was to determine whether the time of their development coincides with known maturational events that occur in Leydig cells, particularly during the peripubertal period. Testes from rats at 20, 30 and 40-days-of-age as well as testes from mature rats weighing more than 500 gm were prepared for ultrastructural analysis. It was found that digitations form between 20 and 30-days-of-age. These structures varied from simple tubular projections to complicated branched structures, suggesting that digitations are more than simple invaginations of microvilli into coated vesicles as previously described. Subplasmalemmal linear densities were also observed within macrophages juxtaposed to Leydig cells. Collagen was commonly observed between macrophages and Leydig cells in animals 20 days old. These studies demonstrate that although macrophages are present in the testis in maximal numbers at 20 days-of-age, they do not form junctions with Leydig cells until day 30. This is just prior to the major increase in secretory activity of rat Leydig cells that occurs during puberty.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00302977
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  • 44
    Digitale Medien
    Digitale Medien
    Interstitial cells associated with the deep muscular plexus of the guinea-pig small intestine, with special reference to the interstitial cells of Cajal (1992)
    Springer
    Cell & tissue research 268 (1992), S. 205-216 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Intestine ; Interstitial cells ; Pacemaker ; Electron microscopy ; Guinea-pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Interstitial cells associated with the deep muscular plexus of the guinea-pig small intestine were studied by electron microscopy, and three-dimensional cell models were reconstructed from serial ultrathin sections with a computer graphic system. Three types of cells were recognized. The first type was similar in shape to smooth muscle cells, but did not contain an organized contractile apparatus. Many large gap junctions comprising about 4% of the cell surface were present; they connected cells of the first type to each other, to the second type of cell and to smooth muscle cells of the outer circular layer. The second type of cell had a welldemarcated cell body with long slender processes and was characterized by a large amount of glycogen comprising about 9% of the cell volume. The third type of cell was similar to fibroblasts, and contained well-developed Golgi apparatus and rough endoplasmic retiulum. Some of these fibroblast-like cells (a possible subtype) formed small gap junctions. All three types of cells showed close relationships with nerve varicosities. This cellular network consisting of gap-junction-rich cells, glycogen-rich cells and smooth muscle cells may be involved in the pacemaking activity of intestinal movement.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318788
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  • 45
    Digitale Medien
    Digitale Medien
    12-O-tetradecanoylphorbol-13-acetate induces selective desquamation of superficial cells in rat urinary bladder epithelium (1992)
    Springer
    Cell & tissue research 268 (1992), S. 239-245 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Urinary bladder ; Epithelial desquamation ; TPA ; Electron microscopy ; Rat (Donryu)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 12-O-tetradecanoylphorbol-13-acetate (TPA) is known to affect the proliferation and/or differentiation of several types of cells. We injected TPA directly into the lumen of rat bladder to determine, using scanning and transmission electron microscopy, its effects on the bladder epithelium in vivo. At 1 h after TPA injection (1μg/ml), the superficial cells of the epithelium had changed their morphology, and large spherical vacuoles occupied their cytoplasm. In some areas, the underlying intermediate cells were exposed by the desquamation of the superficial cells. During the next few hours, TPA was excreted from the bladder lumen by voluntary micturition, but the desquamation of the superficial cells proceeded further. All the superficial cells were lost from the luminal surface by 24 h after TPA injection. The changes noted were specific for the superficial cells and were not observed in the intermediate or basal cells. After 24h, part of the epithelium had a three-layer structure, indicating that regeneration was taking place. These results demonstrate that TPA selectively affects and desquamates superficial cells in a short period of time. This experimental system may be useful for studying in vivo cell proliferation and/or differentiation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318792
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  • 46
    Digitale Medien
    Digitale Medien
    Histochemical localization of nucleoside triphosphatase activity in assimilate conducting plant tissue (1992)
    Springer
    Protoplasma 167 (1992), S. 145-151 
    Details
    ISSN: 1615-6102
    Schlagwort(e): ATPase ; UTPase ; Electron microscopy ; Energy-dispersive X-ray microanalysis ; Gomphrena globosa ; Histochemistry ; Hordeum distichon ; Monstera deliciosa ; Phloem
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary For the histochemical localization of nucleoside triphosphatases at the electron microscopic level, prefixed tissues were incubated with lead nitrate in addition to substrate (GOMORI reaction). While ATP and UTP as substrates gave electron-dense reaction products at the plasmalemma of sieve tubes, companion cells and phloem parenchyma cells, and at plasmodesmata in primary pitfields, AMP gave reaction products only at the tonoplast of parenchyma cells. Since electron-dense deposits also occur in cell walls and vacuoles, energy dispersive X-ray microanalysis was used to distinguish between lead deposits and lead-phosphate deposits. The latter were restricted to the symplast. Among the three plant species used, the leaf bundle phloem ofHordeum distichon showed ATPase activity largely restricted to the phloem cells, except for the thickwalled sieve tubes. Some activity also bordered the chloroplasts of the bundle sheath cells. In the C4 plantGomphrena globosa, ATPase and UTPase activities appeared to be the greater in phloem parenchyma cells than in sieve tubes. In the phloem of youngMonstera deliciosa roots, ATPase occurred not only at the plasmalemma of sieve tubes, but also around sieve-tube plastids. When compared with AMP as substrate, it appears that nucleoside triphosphates are the natural substrates of the enzyme(s) in the plasmalemma of sieve tubes and phloem parenchyma cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01403377
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  • 47
    Digitale Medien
    Digitale Medien
    Effects of organic acids on stria vascularis ultrastructure and function in the chinchilla (1992)
    Springer
    European archives of oto-rhino-laryngology and head & neck 249 (1992), S. 168-171 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Cochlea-Stria vascularis ; Electron microscopy ; Endocochlear potential ; Loop diuretics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The purpose of this study was to compare the effects of several organic acids (probenecid, sodium salicylate and penicillin G) on the endocochlear potential (EP) and the ultrastructure of the stria vascularis of the chinchilla with the effects of furosemide on these parameters. chinchillas received 50 mg/kg i.v. doses of probenecid, sodium salicylate or penicillin G, or 25 mg/kg i.v. furosemide. The EP was monitored continuously before and for 60 min afterwards. The stria vascularis was removed at 10-min intervals from animals and from 10 to 60 min after the injection of these agents. Specimens were then processed for transmission electron microscopy. Only furosemide had an effect on the EP, causing a reversible reduction. The reduction of the EP was accompanied by the appearance of edema in the intercellular spaces of the stria vascularis. No significant edema was found after probenecid, sodium salicylate or penicillin G. This was consistent with the finding that none of these latter three agents affected the endocochlear potential.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00183494
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  • 48
    Digitale Medien
    Digitale Medien
    Muscle pathology in idiopathic cricopharyngeal dysphagia (1992)
    Springer
    European archives of oto-rhino-laryngology and head & neck 249 (1992), S. 216-223 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Cricopharyngeal dysphagia ; Muscle biopsy ; Electron microscopy ; Enzyme histochemistry ; Myositis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The structural changes in the cricopharyngeal muscle (CM) were examined ultrastructurally and by enzyme histochemistry in five patients suffering from idiopathic cricopharyngeal dysphagia (ICD). Diagnosis was established by fiberoptic esophagoscopy, esophageal manometry and cineradiography. Cricopharyngeal myotomy was performed with marked improvement in all patients. Intraoperatively, a biopsy was taken from the CM. Additionally, all patients underwent neurological examination for possible generalized muscle disease, and a biopsy was taken from a limb muscle. CM from nine cadavers without known history of dysphagia served as control. The control samples disclosed structural changes which were considered to be pathological in other skeletal muscles, and required that the criteria for CM pathology we modified accordingly. In three patients changes in CM histology suggested specific pathogenesis: one patient had evidence for a generalized myositis but was only symptomatic for dysphagia. Another patient had muscle fiber atrophy and slight inflammation in her CM, possibly due to alcohol abuse. The third patient had loss of CM fibers with replacement by connective tissue enough to cause functional disturbances. In two patients no cause for dysphagia was found in either immunohistochemistry or electron microscopic studies. These results demonstrate the special structural features of the CM and indicate that ICD can have multiple etiologies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00178473
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  • 49
    Digitale Medien
    Digitale Medien
    Extracellular matrix in the rat spiral limbus (1992)
    Springer
    European archives of oto-rhino-laryngology and head & neck 249 (1992), S. 224-230 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Inner ear ; Rat spiral limbus ; Intercellular matrix ; Electron microscopy ; Immunomorphology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The matrix of the spiral limbus is obviously a special form of the intercellular substance. In the present study, the rat's spiral limbus was investigated by electron microscopy after fixation with ruthenium red and tannic acid and immunofluorescence to demonstrate matrix components. Collagen types I, II, V, VI, VII, IX and XI and fibronectin were not observed. Collagen type II and cartilage-specific proteoglycans, however, occurred in large quantities. The basal lamina of interdental cells and inner sulcus cells did not contain any collagen type IV. while the basal lamina of the capillaries had only minor amounts. Laminin and nidogen appeared in large amounts in the basal lamina. After fixation with tannic acid, the matrix between the interdental cells and the capillaries contained 20- to 22-nm-thick single and irregularly running fibrils as well as plaques of a fine granular material. After fixation with ruthenium red, 30-to 60-nm-thick, electron-dense granules occurred and most probably consisted of proteoglycans. These findings indicate that the composition of the matrix of the spiral limbus is similar to that of cartilage but not identical.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00178474
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  • 50
    Digitale Medien
    Digitale Medien
    Neural and infranuclear region changes in outer hair cells in acoustically exposed rabbits (1992)
    Springer
    European archives of oto-rhino-laryngology and head & neck 249 (1992), S. 287-292 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Nerve endings ; Outer hair cells ; Acoustic exposure ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Rabbits were exposed to 100 dB pure-tone sound at 2 kHz for 2 h. Electron microscopy was used to study the relationship between changes in the outer hair cells, afferent nerve endings and efferent nerve endings. There was no relationship found between the degree of changes produced in the afferent nerve endings and that the outer hair cells. However, there was a relationship demonstrable between the degree of changes seen in the efferent nerve endings and the infranuclear region of the outer hair cells. These findings show that acoustic trauma will damage most the infranuclear region of the outer hair cells, while efferent nerve endings are injured next and least affected are afferent nerve endings.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00714495
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  • 51
    Digitale Medien
    Digitale Medien
    Structure and dynamics of adrenal mitochondria following stimulation with corticotropin releasing hormone (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 234 (1992), S. 255-262 
    Details
    ISSN: 0003-276X
    Schlagwort(e): Corticotropin releasing hormone ; Adrenal gland ; Mitochondria ; Sprague-Dawley rat ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: The mitochondria of rat adrenals were investigated qualitatively and quantitatively in different functional states of the adrenal cortex. Following stimulation of the animals with corticotropin releasing hormone (CRH), the corticosterone serum levels reached a maximum 1 hour after stimulation with CRH. The amount of inner mitochondrial membrane within the zona fasciculata increased showing a biphasic time course, with a first maximum 2 hours and a second maximum 8 hours after stimulation. In contrast, a significant rise of mitochondrial volume occurred only 24 hours after CRH stimulation. Therefore, the dense vesicularization of mitochondrial cristae may constitute an early process to enhance the steroidogenic capacity of these cells. Within cells of the transition zone between zona glomerulosa and zona fasciculata, we could depict a special type of mitochondria with characteristic crescent-like cristae only seen after stimulation with CRH. This type of mitochondria may represent an intermediate form between mitochondria of zona glomerulosa and zona fasciculata underlining the impressive transformational capacity of adrenocortical mitochondria. After hypophysectomy, zona fasciculata cells contained mitochondria with tubular inner membranes, representing a hypofunctional state. In contrast, the hypofunctional state after hypophysectomy and the hyperfunctional state after stimulation of the adrenal cortex via CRH injection did not appear to correlate with the morphology of mitochondria from the zona reticularis and adrenal medulla.© Willey-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ar.1092340212
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  • 52
    Digitale Medien
    Digitale Medien
    Elastic fibers in the duct system of the rat submandibular salivary gland (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 234 (1992), S. 335-347 
    Details
    ISSN: 0003-276X
    Schlagwort(e): Anatomy and histology ; Basement membrane ; Collagen ; Connective tissue ; Elastic tissue ; Electron microscopy ; Rats ; Submandibular gland ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: The submandibular salivary gland originates from the floor of the mouth whose mucosa contains elastic fibers. Therefore, such fibers were sought in the duct system of the derivative organ. In adult rats, light microscopy has indeed revealed fine, circumferential, elastic fibers near the basement membrane of the duct epithelium. In the larger extralobular ducts, they were separated from several layers of longitudinal elastic fibers by a capillary-rich zone sparse in elastic fibers except for fine angular ones. More peripherally, larger angular-appearing fibers were frequently present near the submandibular parasympathetic ganglia in the duct wall. As duct diameter decreased, elastic fiber size and number diminished. Intralobularly, the smaller striated ducts, granular and intercalated ducts, and acini generally lacked such fibers. Electron microscopy of the extraglandular portion of the main duct revealed fibrils extending from both fibroblasts and elastic fibers that were close to the epithelium. Microfibrils coursed from them toward the lamina densa. Anchoring filaments joined the lamina densa to the basal plasma membrane of the epithelium. Elastic fibers also appeared to connect to both capillaries and collagen via finer intermediate structures. These associations might permit dynamic interactions of fibroblasts, fibers, smaller fibrillar components, vasa, and the duct epithelium. This interplay could occur during feeding and grooming when tongue protrusion and neck extension stretch the submandibular duct and the gland itself. As a result, the tensile forces engendered could modify cell geometry and the calibers of the larger ducts' lumens and intercellular spaces, thus affecting the flow and composition of salivary secretion.© Willey-Liss, Inc.
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ar.1092340305
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  • 53
    Digitale Medien
    Digitale Medien
    Blood cells of the gilthead seabream (Sparus aurata L.): Light and electron microscopic studies (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 234 (1992), S. 161-171 
    Details
    ISSN: 0003-276X
    Schlagwort(e): Blood cells ; Teleosts ; Gilthead seabream ; Sparus aurata ; Light microscopy ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: The peripheral blood cells of the gilthead seabream (Sparus aurata L.) were studied by light and transmission and scanning electron microscopic methods. Acidophilic erythroblasts and mature erythrocytes, round, oval, and fusiform thrombocytes, neutrophils, acidophils and basophils, lymphocytes, plasma cells, and monocyte-macrophages were characterized. A comparison of our light and electron microscopic results was carried out. The results were discussed with those for other fish species and the main modifications from the common vertebrate haematological pattern observed being considered.© Willey-Liss, Inc.
    Zusätzliches Material: 21 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ar.1092340203
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  • 54
    Digitale Medien
    Digitale Medien
    Primary culture of human fallopian tube epithelial cells and co-culture of early mouse pre-embryos (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 32 (1992), S. 236-242 
    Details
    ISSN: 1040-452X
    Schlagwort(e): Blastocyst ; Pre-implantation ; EGF ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: We have established a monolayer culture system for human fallopian tube epithelial cells. The cells were isolated from tubes using collagenase digestion, and were cultured in Ham's F-10 supplemented with 15% fetal calf serum. The epithelial cells derived from culture were characterized using immunocytochemical staining and electron microscopy. These cells were stained with antikeratin and anti-epithelial membrane antigen, but showed no staining after treatment with antivimentin. Electron microscopy showed many microvilli on the cell surface and tight junctions or desmosomes at areas of cell-cell contact. Cell proliferation was enhanced by epidermal growth factor, but not by fibroblast growth factor, insulin, transferrin, estradiol-17β, or progesterone.The 2-cell ICR mouse pre-embryos were co-cultured for 4 days with tubal epithelial cells (A) (n = 98), in cell-conditioned medium (B) (n = 83), or in medium alone (C) (n = 72). During the first 24 h in culture, for groups A and B, the rates of cleavage to the 4-cell stage were 90.9% and 81.9%, respectively. Cleavage rates in these two groups were significantly higher (P =0.0012, P 〉 0.00001) than in group C (56.9%). After 72 h in culture, the rates of development to the blastocyst stage were significantly higher for groups A and B compared to group C (89.6% and 73.5% vs. 54.5%, P 〉 0.00001, P = 0.0002). These results suggest that factor(s) from tubal epithelial cells may facilitate the development of mouse pre-embryos throughout the pre-implantation stages.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mrd.1080320308
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  • 55
    Digitale Medien
    Digitale Medien
    A personal computer based implementation of the maximum-likelihood method of analysis of electron microscope autoradiographs (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 73-86 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Electron microscopy ; Autoradiography ; Maximum-likelihood estimation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The maximum-likelihood (ML) method for the quantitative analysis of electron-microscopic autoradiographs has been shown to be substantially superior to the conventional crossfire (CF) method. It can generate reliable and accurate tracer concentration estimates with far fewer micrographs and produce valid estimates even at counts low enough to preclude the use of the crossfire method while eliminating the need for special ad hoc treatment of narrow membranous structures as well as the secondary verification of the tracer concentration estimates.Despite these significant advantages, the large computational requirements of the ML method has to date hampered its widespread use. In this paper, we present a new line-integration method that allows us to reduce the computational requirements of the ML method to a point where it becomes feasible to implement it on a small computer system of the type typically available to a laboratory user of EM autoradiography. We present the complete line-integration method for the particular case of EM autoradiography with tritium, and show how it can be adapted to other isotopes.We have constructed a software package that implements the complete maximum-likelihood method on the IBM PC class of machines using our line-integration method. Features of this software package which are of particular importance to the research community are device independence, which makes it usable with a large variety of currently available laboratory equipment, and easy portability of the software and data between different computer systems.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070200108
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  • 56
    Digitale Medien
    Digitale Medien
    Preservation and visualization of molecular structure in detergent-extracted whole mounts of cultured cells (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 130-150 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Electron microscopy ; Scanning electron microscopy ; High resolution ; Cytoskeleton ; Biological specimen preparation ; Cultured cells ; Electrophoresis ; Bifunctional crosslinking reagents ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Today's electron microscopes have a resolution sufficient to resolve supramolecular structures. However, the methods used to prepare biological samples for electron microscopy often limit our ability to achieve the resolution that is theoretically possible. We use whole mounts of detergent-extracted cells grown on Formvar-coated gold grids as a model system to evaluate various steps in the preparation of biological samples for high resolution scanning electron microscopy (SEM)Factors that are important in determining the structure and composition of detergent-extracted cells include the nature of the detergent and the composition of the extraction vehicle. Chelation of calcium is extremely important to stabilize and preserve the cytoskeletal filaments. We have also demonstrated both morphologically and by gel electrophoresis that treatment of cells with bifunctional protein crosslinkers before or during extraction with detergent can significantly enhance the preservation of both proteins and supramolecular structures.The methods used to dry samples are a major determinant of the quality of structural preservation. For cytoskeletons freeze-drying (FD) is superior to critical point-drying (CPD), one reason being that CPD samples have to be dehydrated, thereby causing more shrinkage as compared to FD samples. The high pressures to which samples are exposed during CPD may also cause increased shrinkage, and water contamination during CPD causes severe structural damage. We have obtained the best structural preservation of detergent-extracted and fixed cells by manually plunging them into liquid propane and drying over night in a freeze-drayer.The factor that most limits achievement of high resolution in SEM is the metal coat, which has to be very thin, uniform, and free of grain in order not to hide structures or to create artifactual ones. We have found that sputter-coating with 1-3 nm of tungsten (W) or niobium )Nb( gives extremely fine-grained films as well as satisfactory emission of secondary electrons. These samples can also be examined at high resolution by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). The best preservation and visualization of supramolecular structures have been obtained using cryosputtering, in which the samples are freeze-dried and then sputter-coated within the freeze-dryer while still frozen. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070220203
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  • 57
    Digitale Medien
    Digitale Medien
    Quantitative morphology for biologists and computer scientists: I. Computer-aided tutorial for biological stereology (version 1.0) (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 338-346 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Tutorial ; Electron microscopy ; Light microscopy ; Software ; Quantitative morphology ; Stereology ; Morphometry ; Simulations ; Terminology ; Data types ; Sampling ; Hierarchies ; Interpretation of data ; Bio-Matrix Project ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: This paper describes a computer-aided tutorial for biological stereology. Stereology, a type of quantitative morphology, includes a collection of statistical methods that quantify the structural compartments that can be viewed in sections with light and electron microscopy. These methods provide volume, surface, length, shape, and number data, and help define the quantitative relationships among the structural compartments of biological hierarchies. Hierarchies, which connect structural data ranging in size from molecules to organs, serve as a central core to which the data of biological databases can be linked. The tutorial focuses on two objectives. It provides the user primarily interested in using quantitative morphology databases with background information, and offers a set of state-of-the-art tools to researchers wishing to use these methods in the laboratory. The main topics of the tutorial include: introduction to quantitative morphology, symbols/terms, data types, sampling, hierarchies, data interpretation, and utilities. The tutorial runs under the MS-DOS operating system and requires at least an IBM PC AT (or compatible), a color monitor (EGA, VGA), 540 KB of RAM, and 3 MB of hard disk space. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070210409
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  • 58
    Digitale Medien
    Digitale Medien
    Computer assisted data collection for stereology: Rationale and description of point counting stereology (PCS) software (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 347-354 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Quantitative morphology ; Morphometry ; Light microscopy ; Electron microscopy ; PCS System III ; MS-DOS ; UNIX ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The paper describes microcomputer software for point counting stereology. Stereology includes a collection of statistical methods that quantify the images of light and transmission electron microscopy. The methods use test grids placed over images to collect raw data, which includes counts of points, intersections, transections, and profiles. In turn, the counts are included in stereological equations that give estimates of compartmental volumes, surfaces, lengths, or numbers. These parameters describe the composition of a structure in three-dimensional space. The PCS (point counting stereology) System Software III serves as a data collection, storage, and management tool. Users set up point counting protocols without programming, enter data by pressing predefined function (MS-DOS) or alphabetic keys (UNIX), store data in files, select files for analysis, and calculate results as stereological densities. The latest version of the PCS software includes a new user interface and is designed as a research “front end” that can feed data either into the calculation tools of a stereology tutorial (Bolender, 1992, this issue) or into the analysis routines of quantitative morphology databases (Bolender and Bluhm, 1992). © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070210410
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  • 59
    Digitale Medien
    Digitale Medien
    Quantitative aspects of synapses on Golgi-impregnated neurons (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 334-352 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Identified neurons ; Quantification ; Rotating/tilting ; Synaptic contacts ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: With the classical Golgi techniques, numerous types of neurons can be distinguished in the cerebral cortex, each with a specific dendritic geometry and pattern of axonal ramifications. In the present review we describe two techniques which allow quantification of synapses on identified neurons: (1) Golgi-rapid impregnation-gold toning-electron microscopy, and (2) Golgi-Kopsch impregnation-gold toning-electron microscopy in combination with staining of the tissue with ethanolic phosphotungstic acid (E-PTA). Both techniques were applied on neurons in the visual cortex of young and adult rabbits. By means of rotating and tilting specimens in the electron microscope, the nondistinctive ultrastructure of obliquely sectioned synapses can be circumvented, leading to precise estimates of asymmetrical vs. symmetrical synapses without complete reconstruction of the neuron. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070230408
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  • 60
    Digitale Medien
    Digitale Medien
    Peripheral sensilla of some lower invertebrates: The platyhelminthes and nematoda (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 285-297 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Electron microscopy ; Evolution ; Flatworms ; Nematodes ; Nervous system ; Review ; Sense organs ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The flatworms (Platyhelminthes) and the round worms (Nematoda) are phylexhibiting strikingly different levels of cellular organization. In both, sensilla are composed of the endings of sensory dendrites intercalated into their epidermis.In flatworms, sensilla that penetrate the syncytial epidermis bear sensory processes derived from cilia. In free-living species, the sensory processes more closely resemble motile cilia, while in parasites, greater deviations occur from the classical cilium pattern. Estimates of the function of the various sensilla have been largely arbitrary, and remain based on ultrastructural features.Sensilla in round worms lie below or within a heavy secreted cuticle. Two glia-like cell types occur. The socket cell mediates contact with cuticle and is responsible for cuticular modifications essential for operation of the sensillum. The sheath cell forms a receptor cavity around the sensory processes and regulates its environment. Sensory processes vary greatly from the classical cilium pattern. Absence of a basal body, but preservation of a ciliary necklace, suggests that the latter has a primary importance in sensory transduction. Estimates of function are based largely on ultrastructural features and analogies to arthropod sensilla. Genetic studies with the free-living nematode Caenorhabditis are beginning to demonstrate details of function and development.Speculations on the roles of basal bodies, rootlets, and vesicles and on the significance of recessed sensilla are given. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 26 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070220306
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  • 61
    Digitale Medien
    Digitale Medien
    Phylogeny of the vomeronasal system and of receptor cell types in the olfactory and vomeronasal epithelia of vertebrates (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 1-21 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Cilia ; Microvilli ; Ultrastructure ; Electron microscopy ; Evolution ; Cladistics ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: In this paper, the evolutionary origin of the vomeronasal system as a discrete sensory system separate from olfaction is examined. The presence of a discrete vomeronasal system appears to be a derived character in tetrapods, and its presence in larval amphibians indicates that the system did not arise as a terrestrial adaptation. The vomeronasal system has been lost independently in several taxa, including crocodilians, some bats, cetaceans, and some primates. The presence of microvillar receptor cells in the vomeronasal epithelium appears to be the ancestral condition for tetrapods, and alternative hypotheses concerning the ancestral condition for receptor cell types in the vertebrate olfactory epithelium are discussed. Finally, the possibility that the vomeronasal system is present in some fishes in a form that has not been recognized is discussed in relation to the phylogenetic distribution of receptor cell types in vertebrates. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070230102
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  • 62
    Digitale Medien
    Digitale Medien
    Fine structure of olfactory epithelia of gastropod molluscs (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 307-324 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Sensory ; Chemosensory ; Ultrastructure ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Among gastropod molluscs the chemical senses are most important for location of distant objects. They are used in food finding, locating mates, avoiding predators, trail following, and homing. Chemoreceptors are commonly associated with the oral area, the tentacles, and the osphradium, which lies in the mantle cavity.Most chemosensory neurons are primary sensory neurons, although secondary sensory cells have been reported in the osphradium of some prosobranch gastropods. Most chemosensory organs contain sensory cells with ciliated sensory endings that are in contact with the external environment. Some sensory endings have only microvilli or have no surface elaborations. Cilia on sensory endings are commonly of the conventional type, but some species have modified cilia; some lack rootlets, some have an abnormal microtubular content, and some have paddle-shaped endings. The perikarya of sensory neurons may be within the sensory epithelium, below it, or in ganglia near the sensory surface. In some groups of gastropods there are peripheral ganglia in the olfactory pathway; in others chemosensory axons appear to pass directly to the CNS.Olfactory epithelia of terrestrial pulmonates have modified brush borders with long branching plasmatic processes and a spongy layer of cytoplasmic tubules which extend from the epithelial cells. Sensory endings of the olfactory receptors are entirely within this spongy layer. Aquatic pulmonates may have a similar spongy layer in their olfactory epithelia, but the cilia of sensory endings, as well as motile cilia of epithelial cells, extend well beyond the spongy layer. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 36 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070220402
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  • 63
    Digitale Medien
    Digitale Medien
    The aesthetasc concept: Structural variations of putative olfactory receptor cell complexes in crustacea (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 325-335 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Sensilla ; Electron microscopy ; Sexual dimorphism ; Homology ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The structure of the aesthetascs has been investigated in the prawn Macrobrachium rosenbergii (larvae and juveniles), the opossum shrimp Neomysis integer, the euphausid Meganyctiphanes, and in the water-fleas Daphnia magna and D. longispina. The aesthetascs, that are thought to represent olfactory receptors, exhibit a considerable structural variation, ranging from the well known aesthetascs of higher crustaceans (lobster, crab, crayfish) to the corresponding sensilla found in the water-fleas and the males of opossum shrimps. The two following morphological characteristics of the aesthetascs are thought to indicate an olfactory function: the shape of the cuticular hair that is long and essentially hose-shaped, and the thin, loosely arranged cuticle of at least the outer part of the cuticular hair. The presence of other structural elements such as sensory cells, cilia, and enveloping cells are vital for the olfactory function, but the development is variable, which makes their use in the morphological definition of aesthetascs problematic. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 20 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070220403
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  • 64
    Digitale Medien
    Digitale Medien
    Fine structure of olfactory sensilla in myriapods and arachnids (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 22 (1992), S. 372-391 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Olfactory chemoreceptors ; Electron microscopy ; Wall structures ; Sheath cells ; Dendrites ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Structural features of various types of olfactory sensilla are reviewed. (1). Sensilla basiconica which differ in form and size are found on the antennae of centipedes and millipedes. Their walls show longitudinal slits or grooves that either open into the sensillum lumen or do not penetrate the cuticle. In other such sensilla the outer surface is pierced by pores and the inner surface grooved and pocketed. These sensilla are innervated by one to six sensory cells. Their unbranched outer dendritic segments extend to the tip of the sensillum. The sensory cells are surrounded by two or three sheath cells which terminate at the sensillum base or form a continuous tube around the entire length of the outer dendritic segments. (2) Temporal organs of centipides are located between the insertion of the antenna and the ocelli. These sensilla consist of a shallow cuticular ring with a central sensory plate made up by a layer of unperforated cuticle or a capsule with a mushroom-shaped structure inside formed by fibrous-looking cuticle. A dozen sensory cells with unbranched outer dendritic segments innervate each sensillum. They extend toward the sensory cuticle and pass just below it. Numerous sheath cell processes run parallel to the outer dendritic segments up to the sensory cuticle. (3) Thread-like flagella of Pauropoda are found on the antennae. They possess a flexible unperforated cuticular wall. These sensilla contain nine sensory cells surrounded by several sheath cells which form a continuous cytoplasmic tube around the outer dendritic segments. (4) Single-walled sensilla with numerous plugged pores penetrating the cuticular wall occur on the tarsus of the first leg in ticks. Each sensillum is innervated by 4-15 sensory cells. Three sheath cells terminate in the base of the sensillum. (5) Double-walled sensilla with spoke canals are found on the first tarsus of ticks. Their shaft is longitudinally grooved. Pore canals lead inward from the bottom of the grooves and open into vase-shaped chambers. From its base these canals extend into the lumen of the sensillum which contains unbranched outer dendritic segments of 1-2 sensory cells. (6) Single-walled sensilla with pore openings occur on the distal tarsal segments of the first leg of whip spiders. These sensilla are innervated by 40-45 sensory cells. Their unbranched outer dendritic segments fill the shaft lumen and extend partly into the wall pores. Microvillus-shaped sheath cell processes line the inner surface of the cuticular wall. (7) Tarsal organs are located dorsally on the tarsus of all legs and pedipalps of spiders. These sensory organs consist of a cuticular capsule with a dome-shaped projection inside. It is situated on the proximal sidewall of the capsule and possesses 7 pore canals that enclose the dendritic tips of 2-3 sensory cells, giving a total of 20 sensory cells. Each group of dendrites terminating in an individual pore canal is encased by 2 sheath cells. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070220406
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  • 65
    Digitale Medien
    Digitale Medien
    Ultrastructural diagnosis of human pituitary adenomas (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 20 (1992), S. 107-135 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Electron microscopy ; Endocrine neoplasm ; Pituitary adenomas ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Electron microscopy, which has been instrumental in the characterization of normal pituitary cell types, has also played a crucial role in the mirphologic classification pituitary adenomas arising in the presently known 5 cell types, and in the recognition of 3 adenoma types with yet undisclosed cell derivation. This review deals with the application of electron microscopy for study of pituitary adenomas in order to provide specific pathological diagnosis and aid the clinician in selecting appropriate postoperative treatment. In addition to the ultrastructural appearance and diagnostic features of 15 adenoma types, the morphology of hyperplastic proliferations and that of known normal counterparts of various adenoma types are also discussed. Specific morphologic diagnosis of pituitary lesions is important not only for adequate postoperative management of patient, but is also a prerequisite for study of the natural history and biological behaviour of various adenoma types.
    Zusätzliches Material: 36 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070200202
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  • 66
    Digitale Medien
    Digitale Medien
    The ultrstructure of neuronal-pinealocytic interconnections in the monkey pineal (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 124-135 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Pinealocyte ; Pineal-neuron ; Synapses ; Ribbon synapse ; Innervation ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Recent ultrastructural studies of neuronal-pinealocytic interconnections in the monkey pineal are reviewed. The pinealocytes in the adult monkey show almost all of the cytological specializations known in subprimate mammals. Adjacent pinealocytes are functionally coupled through ribbon synapses on cell bodies and gap junctions on cell bodies and cell processes. The pinealocytes receive direct synaptic contacts of nerve fibers with cholinergic terminal morphology. Nerve cells restricted to the central portion of the pineal receive synaptic contacts with more than three different morphologically defined types of nerve terminals. In addition to nerve terminals containing small clear vesicles or vesicles of pleomorphic morphology, a pinealocyte's terminal process containing the synaptic ribbon forms a true synaptic contact on the nerve cell body. The diversity of synapses on these nerve cells strongly suggests multiple origins of these neurons rather than a single peripheral parasympathetic origin. The possible involvement of pineal neurons in an intrinsic circuit that regulates the function of pinealocytes and integrates the neural input from the central as well as the peripheral nervous systems is discussed.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070210205
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  • 67
    Digitale Medien
    Digitale Medien
    Fine structure of the vomeronasal and septal olfactory epithelia and of glandular structures (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 86-97 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Accessory olfactory ; Nasal glands ; Odorant binding protein ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The vomeronasal and septal olfactory organs are two neurosensory structures in the mammalian nasal septum which are poorly understood relative to the main olfactory system. The vomeronasal organ is a paired, blind-ending tubular structure that opens rostrally into the nasal cavity in some species and into the incisive ducts in others. When present in mammals, the septal olfactory organ is an island of olfactory mucosa positioned such that it is in the primary air pathway in the caudal portion of the nasal cavity. Mammalian nasal glands, with a diverse histochemical and ultrastructural morphology, secrete a variety of substances onto the mucosal surface. One of these substances, odorant binding protein, localized in bovine nasal glands and lateral nasal glands of rodents may be important in the capture and conveyance of odorant molecules to olfactory receptors. The objectives of this paper are to present original data while reviewing the literature on the ultrastructure of vomeronasal and septal olfactory neuroepithelia, and of vomeronasal, bovine nasal, and lateral nasal glands. Nasal tissues from pigs, calves, and hamsters were prepared for electron microscopy. Neurosensory epithelia of the porcine vomeronasal organ and the hamster septal olfactory organ are similar to that described for the vomeronasal and septal olfactory organs of other mammals. Bovine nasal and rodent lateral nasal glands consist of subregions which differ morphologically; the most abundant acinar cell type in the bovine nasal gland contains lightly electron dense secretory granules while that of the rodent lateral nasal gland contains both small electron dense and large, electron lucent granules. The porcine vomeronasal gland contains numerous small, dense granules of a diverse morphology. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 17 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070230108
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  • 68
    Digitale Medien
    Digitale Medien
    Dynamics of golgi impregnation in neurons (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 23 (1992), S. 264-274 
    Details
    ISSN: 1059-910X
    Schlagwort(e): CNS ; Light microscopy ; Electron microscopy ; Cerebral cortex ; Nerve cell ; Impregnation method ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: This paper describes the early stages of impregnation by the Golgi rapid method in sections and blocks of brain tissue. Aldehyde-fixed and potassium dichromate-treated sections of cerebral cortex were placed on glass slides and coverslipped. The dichromate solution was then replaced by a silver nitrate solution, and events taking place in the section were monitored and time-lapse recorded until the impregnation was interrupted and the sections subsequently prepared for electron microscopy. The tissue blocks, fixed and chromated in the same way, were placed into a silver nitrate solution for 30 min to 24 h and the progress of impregnation compared with the results obtained in the sections on the glass slides.Two basic modes of impregnation were observed, apparently in direct relation to the process of crystallization of silver chromate: crystals of silver chromate growing directly from the surface of the tissue into the nerve cell via its transected plasma membranes, and microcrystalline precipitate of silver chromate spreading into the nerve cell from nucleation centres dispersed in the tissue. The precipitate grows inside the cell as in a preformed channel until the cell has been filled. If the nucleation begins extracellularly, the precipitate extends into the narrow intercellular gaps. Electron microscopy showed that the crystalline precipitate consisted of multilamellar formations containing dense coalesced granules that did not cross plasma or endocellular membrane boundaries. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 38 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070230403
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  • 69
    Digitale Medien
    Digitale Medien
    Comparison of nuclear hydration in boar spermatozoa before and after freeze-thawing: Contrast analysis of cells embedded in bromide-labeled medium (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 249-254 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Electron microscopy ; Water ; Image analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: Epon labeled with bromide was used to embed ejaculated and freeze-thawed spermatozoa, with the hypothesis that it replaces most of cell water. Image analysis of relative contrasts between sperm nuclei and the surrounding medium revealed that when used in low concentrations, bromide is mostly absorbed to the nuclear structures. For higher concentrations, the chromatin is saturated, and the increase in contrast can be used to calculate relative differences in the hydration of nuclei. Boar sperm nuclei are more hydrated after freeze-thawing than before. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070210308
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  • 70
    Digitale Medien
    Digitale Medien
    Computer-assisted morphometry: Point, intersection, and profile counting and three-dimensional reconstruction (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Microscopy Research and Technique 21 (1992), S. 262-270 
    Details
    ISSN: 1059-910X
    Schlagwort(e): Stereology ; Software ; Coordinate geometry ; Volume density, Surface density ; Numerical density ; Serial sections ; Light microscopy ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Allgemeine Naturwissenschaft
    Notizen: The use of computers in morphometry can involve (1) automated image analysis, semiautomated image analysis and point, intersection, intercept and profile counts of two-dimensional images on tissue sections with mathematical extrapolation to the third dimension, (2) direct measurement of volumes, surfaces, lengths, and curvature using x,y,z coordinates of serial sectioned images, or (3) stereologic techniques and serial sections which is a combination of 1 and 2 above. Automated and semiautomated image analysis are generally restricted to specimens that are characterized by differential contrast such as interalveolar septa in the lung or histochemically stained mucous granules in pulmonary epithelium. Point, intersection, and profile counts using hand-held, notebook PCs, portable PCs, or standard PCs and MS-DOS - based application programs are extremely efficient, precise, affordable, and convenient methods of quantitating average values of a population. When morphometric measurements of individual structures are required, computer-assisted three-dimensional reconstruction using x,y,z coordinates of the surface outline from serial sections is a tedious yet precise method. We describe a computer program that efficiently estimates mean caliper diameter, volume, and surface area with less than five percent error with five sections per structure. We also describe a program that does digital image subtraction on serial sections, superimposes digitally generated test systems on biological images, and accumulates point, intersection, and profile counts using a Macintosh II series computer. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jemt.1070210403
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  • 71
    Digitale Medien
    Digitale Medien
    Late changes of irreversible post-partum renal failure (1975)
    Springer
    Virchows Archiv 367 (1975), S. 171-179 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Kidney failure ; Pregnancy ; Electron microscopy ; Hemolytic-uremicsyndrome ; Basement membrane ; Endothelium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The clinico-pathological data from a patient with irreversible post-partum renal failure (IPRF) are presented. The electron microscopy of the late changes are described for the first time and consists of: 1. Thickening of the basement membrane. 2. Interposition of mesangial cells and matrix between the thickened basement membrane and the endothelial cell encircling the periphery of the tuft. 3. Multiplication of basal lamina material between mesangial cells and endothelial cells. 4. Proliferation of endothelial cells. All of the above changes tend to obliterate the glomerular tufts and transform the vascular lumina into slit-like spaces. They explain morphologically why most patients with IPRF terminate in chronic renal failure, if they survive the early changes. The late occurring hypertension is regarded as a secondary stimulation of the renin-angiotension system caused by partial or complete occlusion of arteries and arterioles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430705
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  • 72
    Digitale Medien
    Digitale Medien
    Zur Ultrastruktur fibröser und histiocytärer Hauttumoren (Dermatofibrom, Dermatofibrosarcoma protuberans, Fibroxanthom und Histiocytom) (1975)
    Springer
    Virchows Archiv 368 (1975), S. 253-274 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Tumors of the skin ; Histogenesis ; Classification ; Labyrinth nuclei ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es wird über den Feinbau folgender Hauttumoren berichtet: Dermatofibrom (7 Fälle), Histiozytom (4 Fälle), Dermatofibrosarcoma protuberans (1 Fall) und Fibroxanthom (1 Fall). Aufgrund ihrer unterschiedlichen ultrastrukturellen Merkmale ist eine zweifache Unterteilung dieser Hauttumoren möglich: In eine Tumorgruppe, umfassend das Dermatofibrom, Dermatofibrosarcoma protuberans und Fibroxanthom, bei der die Faserbildung im Vordergrund steht und für deren Histogenese Fibroblasten angenommen werden können. Diese Tumortypen unterscheiden sich vom Histiozytom, dessen Zellcharakter vor allem durch die stark ausgeprägte Phagozytose- und Speichertätigkeit (Fett und Hämosiderin) bestimmt wird und für welches eine histogenetische Ableitung von Histiozyten wahrscheinlich ist. Die Zellkerne des Dermatofibromes und des Histiozytomes weisen einen einfachen Oberflächenverlauf auf, die des Dermatofibrosarcoma protuberans und Fibroxanthomes haben hingegen sehr stark gegliederte Formationen („Labyrinthkerne”). Diese Kernsegmentierung ist für das Dermatofibrosarcoma protuberans ein morphologisches Korrelat seiner Semimalignität. Eine Klassifizierung der faserbildenden Tumoren als „fibröse Histiozytome” erscheint aufgrund der ultrastrukturellen Analyse nicht gerechtfertigt.
    Notizen: Summary A report on the ultrastructure of the following skin tumors: dermatofibroma (7 cases), histiocytoma (4 cases), dermatof ibrosarcoma protuberans (1 case), and fibroxanthoma (1 case). Because of their different ultrastructural characteristics a division into two groups is possible: one group of tumors would include dermatofibroma, dermatofibrosarcoma protuberans, and fibroxanthoma, where the formation of fibers is extensive and fibroblasts are suggested for its histogenesis. These types of tumor differ from histiocytoma, the cellular character of which is determined by a very pronounced phagocytosis and storage of lipid and hemosiderin; a histogenesis from histiocytes is probable. The nuclei of dermatofibroma and histiocytoma show a simple surfacedevelopment, whereas the nuclei of dermatofibrosarcoma protuberans and fibroxanthoma show multisegmented nuclei (“labyrinth nuclei”). In the case of dermatofibrosarcoma protuberans this kind of nuclear segmentation seems to be a morphologic correlate of its semimalignancy. Based on ultrastructural analysis a classification of these fiber-producing tumors into “fibrous histiocytomas” is not justified.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432527
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  • 73
    Digitale Medien
    Digitale Medien
    Déficit en alpha-1-antitrypsine chez l'enfant (1975)
    Springer
    Virchows Archiv 369 (1975), S. 19-27 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Alpha-1-antitrypsin deficiency ; Liver ; Electron microscopy ; Endoplasmic reticulum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Fourteen liver biopsies from twelve young patients with liver diseases associated with homozygous, PiZZ phenotype, alpha-1-antitrypsin deficiency in their sera were examined by electron microscopy. In all these biopsies characteristic homogeneous material was found in some hepatocytes and corresponded, when observed on adjacent semithin sections by light microscopy, to the deposit stained by periodic acid Schiff reaction. The accumulation in perinuclear spaces resulted in intranuclear invaginations, but the major deposit was located in lumens of the endoplasmic reticulum. The limiting membranes were rough and smooth but the extent of the latter was so large that only this type of reticulum seemed peculiarly involved in the accumulating process. On the contrary, Golgi complexes did not seen obligatorily involved by this process because, when observed, they appeared almost normal even in heavily overloaded liver cells. At least for the PiZZ phenotype, the abnormal substance would be an asialo form of normal alpha-1-antitrypsin. Thus the subject of this study is the morphologic translation of an impairment in the synthesis of a glycoprotein. In the light of data concerning the synthesis of such proteins our findings lead us to suggest: The ultrastructural patterns observed in alpha-1-antitrypsin deficiency cannot give the expected morphologic evidence of the biochemical data which locate the first binding steps of monosaccharide residues in the rough endoplasmic reticulum. The absence of sialic acid could not result from an enzymatic defect primarily located in Golgi complexes but could be secondary to an impairment in the binding of one monosaccharide residue which improves subsequent fixation of sialic acid, in the smooth endoplasmic reticulum. Finally it seems necessary to emphasize that the relationship between the abnormal substance and various important non specific lesions is largely unknown and that we don't know the significance of polymorphous dense bodies observed in ductular cells during the cholestatic period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432458
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  • 74
    Digitale Medien
    Digitale Medien
    Ultrastructural localization of plasma lipoproteins in human intracranial arteries (1975)
    Springer
    Virchows Archiv 369 (1975), S. 111-121 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Atherosclerosis ; apoB ; LDL ; VLDL ; Immunoperoxidase ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The fine-structural localization of apoB, the major protein constituent of both the low and very low density plasma lipoprotein fractions, was described in human middle cerebral and basilar arteries. Using an immunoperoxidase technique together with electron microscopy, apoB was localized only in arteries with atherosclerotic involvement and to the following regions in these arteries: 1. on the outer aspects of extracellular spherical structures with diameters of 250 to 700 Å found predominantly in lipid cores and between bands of collagen fibers of advanced atherosclerotic lesions; 2. on the surface of reduplicated elastica; 3. along collagen fibers and; 4. on aggregates of extracellular spherical lipid globules. These results suggest that the extracellular spheres may represent the fine-structural morphology of deposited low and very low density lipoproteius and that free apoB may be bound to lipid globules, elastica, and collagen fibers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00433237
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  • 75
    Digitale Medien
    Digitale Medien
    Ultrastructural study of calcium-containing precipitation in human parathyroid glands (1975)
    Springer
    Virchows Archiv 368 (1975), S. 99-108 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Electron microscopy ; Calcium ; Parathyroid glands ; Chief cells ; Oxyphil cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Using the potassium pyroantimonate technique for ultrastructural localization of cations and X-ray elemental analysis with both energy dispersive and wave-length dispersive systems, calcium-containing precipitates were found in normal, hyperplastic and adenomatous human parathyroid glands. Differences were observed between oxyphil cells, and suppressed, stimulated and active chief cells in the content and localization of intracellular precipitation. The oxyphil cells and suppressed chief cells possessed precipitates mainly in nuclei and medium-sized and large mitochondria, whereas the stimulated chief cells possessed precipitates in normal-appearing and morphologically altered mitochondria, and in smooth-surfaced vacuoles and cytosol. The active chief cells usually showed a rather sparse precipitation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432411
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  • 76
    Digitale Medien
    Digitale Medien
    Vinblastine-induced ultrastructural changes in perisinusoidal cells of the rat liver (1975)
    Springer
    Research in experimental medicine 165 (1975), S. 245-249 
    Details
    ISSN: 1433-8580
    Schlagwort(e): Vinblastine ; Liver ; Perisinusoidal cell ; Microtubules ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Vinblastine, given intravenously to rats, leads to disappearance of microtubules, formation of paracrystalline inclusions and accumulation of fat droplets in the cytoplasm of the perisinusoidal cells of the liver suggesting that microtubules of the perisinusoidal cells play a role in lipid metabolism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01971384
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  • 77
    Digitale Medien
    Digitale Medien
    An ultrastructural comparison of implantation in young and senescent golden hamsters (1975)
    Springer
    Anatomy and embryology 147 (1975), S. 293-307 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Implantation ; Golden hamster ; Senescent ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Implantation was compared in young (3–5 month) and senescent (14–17 month) golden hamsters at 3, 31/2, 4, 41/2, 5, and 51/2 days of pregnancy (post-ovulation). One hundred twenty-two embryos (89 from 22 young females and 33 from 18 senescent females) located in utero by cutting thick sections (1–3 μm), were re-embedded and thin-sectioned for electron microscopy. Ultrastructurally implantation and embryonic differentiation was delayed approximately 12 hours in the senescent hamster when compared with young hamsters at the same stage of pregnancy. Failure of the blastocyst to implant would not appear to be a major cause of the declining litter size in aged golden hamsters.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315077
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  • 78
    Digitale Medien
    Digitale Medien
    Differentiation of sympathicoblasts in cultures of chick ganglia (1975)
    Springer
    Anatomy and embryology 146 (1975), S. 225-243 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Differentiation ; Sympathetic ganglion ; Culture ; Electron microscopy ; Histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Immature sympathetic ganglia prepared from 51/2- or 6-day-old chick embryos were cultured up to one month. The in vitro development was followed by phase microscopy, electron microscopy and using histochemistry for catecholamines, monoamine oxidase and cholinesterases. During the first week of culture extensive plexuses of nerve fibres were formed between and around the clusters of nerve cells. Mature-looking neurons were observed in the cultures by phase microscopy after three weeks, at which age the mean diameter of the perikarya was more than doubled. Varying catecholamine fluorescence was observed in the perikarya during the entire culture period. The nerve fibres showed usually only weak fluorescence, but, in the older cultures, bright varicosities were regularly found in the fibres. Monoamine oxidase activity was demonstrated already at three days of culture and the reaction was maintained positive. Weak or moderate acetyl-cholinesterase activity was demonstrated in the sympathicoblasts and young sympathetic neurons and their processes. The axolemma showed acetylcholinesterase activity also around the nerve terminals containing small dense cored vesicles. Reactions for the non-specific cholinesterases were negative. Electron microscopy of the 30-day-old cultures revealed that the clusters of nerve cells consisted of mature sympathetic neurons, which contained large (60–200 nm) and small (35–60 nm) granular catecholamine-storing vesicles. Glial cells were almost totally lacking. Large numbers of nerve terminals containing both large and small granular vesicles were observed in the clusters, often in synaptic contact with the sympathetic neurons. It is concluded that the primitive sympathicoblasts are, in favourable conditions, capable of differentiation in culture up to mature sympathetic neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00302172
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  • 79
    Digitale Medien
    Digitale Medien
    In utero development and maturation of the retina of a non-primate mammal: A light and electron microscopic study of the guinea pig (1975)
    Springer
    Anatomy and embryology 146 (1975), S. 279-300 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Retinogenesis ; Synaptogenesis ; Guinea pig ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A light and electron microscopic examination of retinogenesis in the fetal guinea pig has revealed an early development of synapses and photoreceptor cells. Differentiation of the neural retina begins around day 23 of gestation. By 34 days the retina reaches its maximum thickness. It differentiates an inner plexiform layer in which vesicle-containing processes and primitive synapses are evident. Synaptic ribbons are found in processes of this layer by 43–45 days of gestation. An outer plexiform layer develops within the neuroblast layer at 40 days of gestation; from its first appearance the outer plexiform layer contains synapses complete with synaptic ribbons. Receptor terminals of the α, paranuclear and β type are present well before birth. Photoreceptor cells form inner segments by 40 days; the formation of outer segments is indicated by 45 days but not widespread until 49 days. The retina appears mature by day 51–57. It is clear that the primate is not unique in the early differentiation of its retinal synapses relative to the time of maturation of its photoreceptor cells. The potential functional capacities of precocious retinae, and the mechanisms of synapse development are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00302175
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  • 80
    Digitale Medien
    Digitale Medien
    Melanogenesis in the pigment epithelium of chicken embryos (1975)
    Springer
    Anatomy and embryology 147 (1975), S. 177-187 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Iris ; Melanogenesis ; Chicken embryo ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The iris anlage of 2–10 and 15 days old chicken embryos were studied histochemically, and by both light and electron microscopy. Light microscopic serial sections showed that pigmentation began at the outer layer of the posterior eye pole and progressed from there forwards to the optic cup margin. The entire outer layer of the optic cup as well as the pupillary margin were completely pigmented by the 4th day of incubation. By the 10th day the posterior iris epithelium was totally pigmented. Electron microscopical studies showed that the first premelanosomes appeared at about the 3rd day of incubation in the anterior iris anlage with the exception of the pupillary margin. It could be shown that melanogenesis progressed through the following steps: premelanosomes, followed by tyrosinase activity in a Golgi-associated system of smooth endoplasmic reticulum (GERL) and small vesicles and finally differentiation of the melanosomes. The possible origin of the premelanosomes and the formation of melanin are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00306732
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  • 81
    Digitale Medien
    Digitale Medien
    Formation and nature of swirl defects in silicon (1975)
    Springer
    Applied physics 8 (1975), S. 319-331 
    Details
    ISSN: 1432-0630
    Schlagwort(e): Self-interstitials in silicon ; Swirls ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Notizen: Abstract Point defect agglomerates in dislocation-free silicon crystals, usually called “swirls”, have been investigated by means of high-voltage electron microscopy. It was found that a single swirl defect consists of a dislocation loop or a cluster of dislocation loops. By contrast experiments it could be shown that these loops are formed by agglomeration of self-interstitial atoms. Generally the loops have a/2〈110〉 Burgers vectors, but in specimens with high concentrations of carbon (∼1017 cm−3) and oxygen (∼1016 cm−3) also dislocation loops including a stacking fault were observed. In crystals grown at growth rates higher thanv=4 mm/min no swirls are observed; lower growth rates do not markedly affect the size and shape of the dislocation loops. With decreasing impurity content (particulary of oxygen and carbon) the swirl density decreases, whereas the dislocation loop clusters become larger and more complex. A model is presented which describes the formation of swirls in terms of agglomeration of silicon self-interstitials and impurity atoms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00898366
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  • 82
    Digitale Medien
    Digitale Medien
    Vascular and neuroglial changes in experimental herpes simplex encephalitis (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 245-256 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Herpes simplex encephalitis ; Blood-vessels ; Reactive microglia ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Generalized vascular changes and diffused proliferation of reactive microglia were observed in an experimental model of HSV encephalitis of mice. The wide spread of these changes contrasted with the localized character of virus replication and the confined areas of damaged nervous tissue. The vascular and microglial changes were precocious in animals inoculated with concentrated virus suspension (105.5LD50) while they appeared late in mice inoculated with diluted virus suspension (100 LD50). After inoculation with U.V. inactivated virus no changes were seen. The results obtained in this study suggest that the vascular and microglial modifications are not related to a direct cytopathic effect of the virus but dependent on the amount of virus present in the central nervous system and linked to the virus DNA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688397
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  • 83
    Digitale Medien
    Digitale Medien
    Brain involvement in Whipple's disease (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 275-278 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Whipple's disease ; Macrophage ; Electron microscopy ; Brain involvement
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A man of 22 with Whipple's disease suffered from an acute febrile state and unconsciousness. Focal inflammatory lesions accompanied by large numbers of peculiar macrophages occurred in thalamus and basal ganglia. The electron microscopic findings conform to previous reports on brain involvement in Whipple's disease.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688400
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  • 84
    Digitale Medien
    Digitale Medien
    Electron microscopic investigation of inclusion material in a case of adult metachromatic leukodystrophy; Observations on kidney biopsy, peripheral nerve and cerebral white matter (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 165-171 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Adult metachromatic leukodystrophy ; Brain ; Peripheral nerve ; Kidney ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The fine structural characteristics of storage products in peripheral nerve, kidney and cerebral white matter, from a case of adult metachromatic leukodystrophy are described. There were pronounced differences from the fine structural aspects in late infantile cases. A large proportion of the inclusions did not exhibit a unit membrane. An hypothesis is proposed to clarify the delayed manifestation of this type of metachromatic leukodystrophy until adulthood.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00687542
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  • 85
    Digitale Medien
    Digitale Medien
    Niemann-Pick disease (Crocker's type C) (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 191-200 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Niemann-Pick disease ; Storage distribution ; Cerebral vascular glycolipid ; Histochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A histochemical study is reported of regional differences of the lipid storage in a case of Niemann-Pick disease (NPD) type C. Besides tissues known to be affected (reticuloendothelium, hepatocytes, nervous system), storage was demonstrated in adrenal cortical spongiocytes, sweat glands, renal glomerular and tubular cells, smooth muscle, excretory tubules of some salivary glands, ependyma and in choroid plexus. In most tissues were stored sphingomyelin, cholesterol and a small amount of a glycosphingolipid. In the endothelium of cerebral and spinal vessels the main stored lipid was a glycosphingolipid. The significance of these regional differences are discussed and their study is recommended as a useful counterpart to the biochemical investigation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688393
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  • 86
    Digitale Medien
    Digitale Medien
    A study of the perineurium in peripheral nerve pathology (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 257-270 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Perineurium ; Pathology ; Electron microscopy ; Homeostasis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The response of the perineurium to the following experimental systems was investigated by light and electron microscopy: nerve crush, cold lesion and microinjection of (a) histamine liberator, (b) potassium cyanide, (c) lysophosphatidyl choline (LPC). Where myelin breakdown occurred, lipid globules were seen within Schwann cells, macrophages and also perineurial cells. Where increased vascular permeability occurred, proteinaceous material leaked from endoneurial vessels into the endoneurial space and later appeared between perineurial laminae. It is suggested that the normal homeostatic function of the perineurium is extended in pathology to the removal of protein and lipid debris. In this way the perineurium contributes to the restoration of the normal microenvironment of peripheral nerve fibres.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688398
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  • 87
    Digitale Medien
    Digitale Medien
    Symmetrical infantile thalamic degeneration with focal cytoplasmic calcification (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 1-8 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Thalamus ; Cytoplasmic calcospherules ; Non-dystrophic ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Infantile thalamic degeneration is a rare clinico-pathological entity. Restricted location of the lesion and peculiar cytopathological changes serve to distinguish this disorder from other common encephalopathies. Optical and ultrastructural studies demonstrate cytoplasmic calcopherules in previously viable cells. According to current concepts of acute cellular reactions to injury and mechanism of intracellular calcification, the cytological changes cannot be attributed to either hypoxic ischemic cell change or dystrophic calcification. By analogy to other human and pathological material, the most likely basis for nondystrophic calcopherule formation is toxic or infectious injury with local synthesis, or autophagic or phagolysosomal degradation of cellular debris of specific chemical composition favoring calcium deposition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00685959
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  • 88
    Digitale Medien
    Digitale Medien
    Epileptic activity and anatomical characteristics of different lesions in cat cortex. Ultrastructural study (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 143-152 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Electron microscopy ; Experimental epilepsy ; Oedema
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Three different types of lesions have been studied in the cortex of the cat, by means of electroencephalography and electron microscopy. These three types of lesions can be listed in order of increasing magnitude according to their capacity to induce abnormal electrical activity: 1. incision of the cortex gives paroxymal activity, 2. intracortical insertion of a resin pellet generates weak epileptic activity, 3. intracortical insertion of a cobalt resin pellet produces epileptic activity. A parallel can be drawn between electrophysiological and anatomical data: there seems to be a quantitative relationship between the degree of epileptic activity and the extent of perilesional tissue. Furthermore, in this perilesional tissue, oedema is observed, the intensity of which varies according to the type of lesion. Thus, the epileptic activity of a lesion seems to be proportional not only to the volume of the perilesional tissue but also to the development of the oedema.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00687540
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  • 89
    Digitale Medien
    Digitale Medien
    GM2-Gangliosidosis, AB variant (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 207-226 
    Details
    ISSN: 1432-0533
    Schlagwort(e): GM2-Gangliosidosis, AB Variant ; Hexosaminidase A and B ; Electron microscopy ; Membranous cytoplasmic inclusions ; Zebra bodies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Clinical and neuropathological studies of a case of AB variant GM2-gangliosidosis have been presented. The patient was a 14 months old black female infant who had “black cherry spot” in the retinas. The total activities of β-galactosidase and N-acetyl-β-hexosaminidase, as well as the proportion of hexosaminidase A and B components in her serum and leukocytes were normal when the assays were carried out with artificial fluorogenic substrate. Diagnosis of GM2-gangliosidosis AB variant was established by an abnormal increase of GM2-ganglioside in the biopsied brain tissue, similar to classical Tay-Sachs disease. Her clinical manifestation appeared to be similar but somewhat milder than those of classical Tay-Sachs disease. Light microscopic features of the cerebral biopsy were also closely similar to Tay-Sachs disease and Sandhoff disease but gliosis and neuronal loss were less pronounced. Electron microscopic study revealed numerous membranous cytoplasmic bodies (MCB) and zebra bodies in neurons. In addition, varieties of large intracytoplasmic inclusions in astrocytes, a feature distinctly different from classical Tay-Sachs disease, were observed. Numerous cytoplasmic inclusions were also present in oligodendroglia, pericytes and microglial cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688395
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  • 90
    Digitale Medien
    Digitale Medien
    The myocardium in Lafora disease (1975)
    Springer
    Acta neuropathologica 33 (1975), S. 343-349 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Lafora disease ; Myocardium ; Deposits ; Enzame histochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Histological, histochemical and electron microscopic studies on the myocardium of 3 Japanese patients with Lafora disease were carried out. Deposits in the myocardium stained positively with PAS, Best's carmine and Lugol's indine. After digestion of the sections with α-amylase, the deposits disappeared or were less intense, in particular with PAS staining. Phosphorylase activity was deficient in the myocardium of Case 3, when compared with controls, both of which were kept frozen at −20°C following autopsy. Electron microscopy revealed that the deposits were not membrane-bound and consisted of fine particles and fibrillae. The nature of the deposits is diseussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00686166
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  • 91
    Digitale Medien
    Digitale Medien
    Origin and ultrastructure of intra-hyphal hyphae in Trichophyton terrestre and T. rubrum (1975)
    Springer
    Archives of microbiology 106 (1975), S. 195-200 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Trichophyton terrestre ; Trichophyton rubrum ; Hyphal fusions ; Origin of intra-hyphal hyphae ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A cell observation chamber was designed to perform continuous photomicroscopic observations of hyphal anastomosis and the origin of intra-hyphal hyphae in Trichophyton terrestre and T. rubrum. These data were correlated with ultrastructural features of intra-hyphal hyphae. Hyphal fusions occurred commonly in either species of Trichophyton when incubated alone. In T. terrestre, empty hyphal segments adjoined by live units were invaded at the septa from both directions by new hyphal ingrowth. Continuous observations revealed that the intra-hyphal hyphae subsequently anastomosed via a lateral fusion peg. Similar intra-hyphal hyphae were shown in T. rubrum. Electron microscopic studies revealed ascomycetous septa in both conventional hyphae and intra-hyphal hyphae. For the latter, the cytoplasm and wall of the inner hypha were bounded by cytoplasmic organelles and another cell wall of the outer hypha.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00446523
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  • 92
    Digitale Medien
    Digitale Medien
    Micro-autoradiographic studies on host-parasite interactions (1975)
    Springer
    Archives of microbiology 105 (1975), S. 193-199 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Bean ; Rust ; Haustorium ; Sheath ; Autoradiography ; Infection ; Electron microscopy ; Phaseolus vulgaris ; Uromyces phaseoli
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Tritium labeled uredospores of Uromyces phaseoli were produced be feeding the host, Phaseolus vulgaris, with 3H-orotic acid. These spores were allowed to germinate on and to penetrate into a bean leaf. 24 hrs after inoculation, the bean rust had formed the first haustorium. All fungal structures, including the fungus walls, were heavily labeled. No label could be detected in the cells that had come into contact with the hyphae. In the infected host cell, the haustorium was labeled heavily, but the sheath around the haustorium and the host cell remained free of label. These results indicate that no detectable amounts of label leach from the bean rust into the host at this stage of infection although it is known that the rust takes up many metabolites. Since the sheath remains free of label and all fungal structures are evenly labeled, it is concluded that the sheath is formed by the host.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00447137
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  • 93
    Digitale Medien
    Digitale Medien
    Ultrastructure of the integumental melanophores of the coelacanth, Latimeria chalumnae (1975)
    Springer
    Cell & tissue research 163 (1975), S. 383-394 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Skin pigmentation ; Melanocytes ; Melanophores ; Electron microscopy ; Latimeria (Coelacanth)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The integumental melanophores of Latimeria chalumnae were studied by light and electron microscopy. The epidermal melanophore located in the mid-epidermis consists of a round perikaryon with long slender dendrites extending into epidermal cells and intercellular spaces. The dermal melanophores occur in the loose dermal matrix underlying a relatively thick layer of collagen fibers. The dermal melanophores are usually flattened and their dendrites lie parallel to the collagen layer. Both epidermal and dermal melanophores contain oval, electron-opaque melanosomes, large mitochondria, agranular vacuoles of endoplasmic reticulum and microtubules. Microfilaments and RNP particles are less conspicuous. While the peripheral cytoplasm of both dermal and epidermal melanophores is filled with a large number of melanosomes, the perinuclear cytoplasm of many dermal melanophores is occupied by premelanosomes in various stages of differentiation, and that of the epidermal melanophore contains numerous large vacuoles. Despite the scarcity of epidermal melanophores, the epidermal melanin unit is present in the form of melanosome complexes. In addition, the melanophores of Latimeria possess the basic characteristics common to other vertebrates, but they more closely resemble those of lungfish and other aquatic vertebrates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219472
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  • 94
    Digitale Medien
    Digitale Medien
    Comparative histochemical and electron microscopic studies of the sinus and venous walls of the human spleen with special reference to the sinus-venous connections (1975)
    Springer
    Cell & tissue research 163 (1975), S. 519-533 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Human spleen ; Sinus lining cells ; Pulp veins ; Histochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Sinus and venous walls of normal human spleens were studied with enzyme histochemical and electron microscopic methods. Particular attention was paid to the connections between sinuses and veins. Histochemically the sinus lining cells revealed a distinct naphthol-AS-acetate-esterase activity but no reaction for alkaline phosphatase. Venous endothelial cells were positive for the latter but negative for the former enzyme. In the sinusvenous junctional area there were no endothelial cells with reactivity for both enzymes. Electron microscopically both the sinus lining cells and the venous endothelial cells could be clearly characterized and therefore easily distinguished from one another on morphological grounds. There were no clear ultrastructural indications of transitional forms between sinus lining cells and venous endothelial cells in the sinus-venous area. According to these findings, sinus lining cells represent a specialized endothelium, but one with practically no morpholgical similarities to the venous endothelium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218497
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  • 95
    Digitale Medien
    Digitale Medien
    The fine structure of the epidermis of two species of salmonid fish, the Atlantic salmon (Salmo salar L.) and the brown trout (Salmo trutta L.) (1975)
    Springer
    Cell & tissue research 163 (1975), S. 535-543 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Epidermis ; Salmonids ; Mucous cells ; Mucus ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of epidermal mucous cells of two species of salmonid fish has been described. Mucous cells are, next to filament-containing cells, the most commonly encountered cells in fish epidermis. The development of the cells as they progress to the periphery has been characterised. They are initially difficult to distinguish from filament-containing cells: later, they can be recognised by the presence of much smooth-surfaced E.R. The mucigenesis and the subsequent secretion of mucus has been observed and it is essentially comparable to that which occurs in the mucous cells of the mammalian intestine. The mucous layer of the epidermal surface seems to mainly comprise of the products of these mucous cells and the “cuticle” seen in other species has not yet been observed in the salmonid species investigated here.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218498
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  • 96
    Digitale Medien
    Digitale Medien
    Thick filaments in vertebrate smooth muscle (1975)
    Springer
    Cell & tissue research 156 (1975), S. 201-216 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Smooth muscle ; Myofilaments ; Vas deferens ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Smooth muscle cells of the mouse vas deferens fixed with 5% glutaraldehyde contained three types of filaments, namely, thin (50–80 Å) filaments, intermediate (100 Å) filaments and thick (120–180 Å) filaments. However, in 2 out of 16 experiments, under identical conditions, the cells did not contain thick filaments. With OsO4 fixation, thin filaments were not prominent, the most obvious being thick (120–250 Å) and intermediate (100 Å) filaments. After soaking in a modified Ringer solution under no applied tension for one hour, thick filaments (120–180 Å) appeared prominently in smooth muscle cells of the mouse vas deferens and thin filaments were in ordered bundles. By 4 hours, thick filaments had increased in size and density, with thin filaments distributed randomly around them. After 8 hours in Ringer, thin filaments were diffuse and difficult to discern, while thick filaments were large (up to 300 Å) and electron-dense. Intermediate (100 Å) filaments were present in association with dark bodies. Physiological experiments indicated that the intracellular components responsible for the development of a mechanical response were still functional at this time. The presence of “thick filaments” is also reported in degenerating smooth muscle cells of the guinea-pig vas deferens in tissue culture.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221803
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  • 97
    Digitale Medien
    Digitale Medien
    Distribution and dimension of the T-system in different muscle fiber types in the Atlantic hagfish (Myxine glutinosa, L.) (1975)
    Springer
    Cell & tissue research 157 (1975), S. 1-16 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Muscle fiber types (Myxine glutinosa, L.) ; T-system ; Growth ; Shrinkage ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Triad density relative to sarcomeres, size of T-system tubules, sarcomere length, muscle fiber diameter in native and fixed states, and size of myofibrils were measured in four striated muscle fiber types in Atlantic hagfishes (Myxine glutinosa, L.) of different sizes. Triads occur at A/I — junctions in all fiber types. The density of triads relative to sarcomeres is higher in “white” than in “red” muscle fibers. The T-tubules show no sign of branching. The area of the T-system tubules is 3–4 times the surface area in 80 μm “white” muscle fibers and 1–2 times that in 60 μm “red” fibers. The size of myofibrils is similar in “white”, “intermediate”, and “red” fibers of m. parietalis, and constant through a large span of animal size. In “white” fibers, increase in diameter up to 90 μm is accompanied by an increase in the number of myofibrils, not by an increase in the individual size of the myofibrils. Above 90 μm, “white” fibers grow by increasing the amount of intermyofibrillar space. This is reflected by an extensive shrinkage of the thicker “white” fibers during the preparative procedure for electron microscopy, a shrinkage that is limited only by complete packing of the myofibrils. “Red” fibers shrink much less.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223227
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  • 98
    Digitale Medien
    Digitale Medien
    Ultrastructure and fluorescence histochemistry of endocrine (APUD-type) cells in tracheal mucosa of human and various animal species (1975)
    Springer
    Cell & tissue research 158 (1975), S. 425-437 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Tracheal epithelium (human, animal) ; APUD-Endocrine system ; Electron microscopy ; Histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This study describes distinctive cells with ultrastructural and histochemical features of APUD-type endocrine cells within the tracheal epithelium of human fetuses, newborns and children as well as different animal species. These cells referred to as Kultschitzky cells (K cells) were found to be argyrophilic, but not argentaffin, and are considered analogous to the same type of cells in lung and gastro-intestinal tract. Fluorescence histochemistry demonstrated the presence of intracellular amine within tracheal K cells, but only after in-vitro or in-vivo administration of amine precursor (L-DOPA). Ultrastructurally, these cells are characterized by the presence of numerous cytoplasmic granules (dense core vesicles) which show species related morphologic variations. Two different types of K cells were found in trachea of lamb and armadillo, each type possessing morphologically different dense core vesicles. In human and rabbit tracheas, only one type of K cell was identified. K cells in the trachea are distributed as single cells between other epithelial cells; neuroepithelial bodies such as those found in bronchial mucosa were not identified. Well differentiated K cells were found in tracheas of early human fetuses and throughout gestation, infancy, and childhood. Preservation of K cells in human autopsy material and widespread occurrence of these cells in various laboratory animals will permit further studies into the nature and function of tracheobronchial endocrine cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220210
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  • 99
    Digitale Medien
    Digitale Medien
    The dormant buds of Rhabdopleura compacta (Hemichordata) (1975)
    Springer
    Cell & tissue research 159 (1975), S. 387-397 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Dormant bud (Rhabdopleura) ; Capsule ; Winter survival ; Yolk store ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Rhabdopleura has an overwintering stage that consists of two layers of cells surrounding a central yolk mass. This cellular part is surrounded by a thick electron dense capsule which is secreted by the bud itself. The capsule is probably impervious and protective to its contents. Blood vessels join the buds to the zooids of the colony. They form the probable route of transfer of yolk from the zooids to the dormant bud. The capsule of the dormant bud has some structural features in common with the black stolon of the adult zooids. The black stolon is probably formed in a manner similar to that which made the fusellar fabric of the periderm of fossil graptolities.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221785
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  • 100
    Digitale Medien
    Digitale Medien
    Aminergic nuclei in the hypothalamus of the roach Leuciscus rutilus (1975)
    Springer
    Cell & tissue research 159 (1975), S. 493-502 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypothalamus ; Teleost ; Aminergic nuclei ; Falck-Hillarp method ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the hypothalamus of the roach (Leuciscus rutilus) green and yellow fluorescent cells were found in the nucleus recessus lateralis (NRL) and the nucleus recessus posterioris (NRP) and green fluorescent cells in the nucleus recessus preopticus (NRPO). The green fluorescence indicates the presence of noradrenaline or dopamine and the yellow one the presence of 5-hydroxytryptamine. The cells of the NRL and NRP contained electron dense granules averaging 70 nm in diameter. The NRL is divided into two parts. These and the NRP are connected by large fluorescent tracts. The NRL and NRP send axons towards the nucleus lateralis tuberis (NLT) and the NRPO sends axons towards the nucleus preopticus (NPO). It could not be established whether the aminergic nuclei described are the origin of the fluorescent fibers in the hypophysis of the roach.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00221705
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