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  • 1990-1994  (70)
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  • 1
    Electronic Resource
    Electronic Resource
    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
    Keywords: Human cutaneous leishmaniasis ; Skin ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01611181
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  • 2
    Electronic Resource
    Electronic Resource
    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
    Keywords: Kidney ; Glomerulus ; Mesangium ; Mesangial failure ; Electron microscopy ; Animal models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00180755
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  • 3
    Electronic Resource
    Electronic Resource
    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
    Keywords: Human brain tissue ; Natural mummification ; Histology ; Histochemistry ; Electron microscopy ; Elemetal analysis ; Gehirn ; Mensch ; Naturaliche Mumifikation ; Histologie ; Histochemie ; Elektronenmikroskopie ; Atmospektralanalyse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: 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.
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01625172
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  • 4
    Electronic Resource
    Electronic Resource
    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
    Keywords: Carnitine-palmityl-transferase deficiency ; Acute vascular lesions ; Acute myofibrillar lesions ; Ischaemia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01607140
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  • 5
    Electronic Resource
    Electronic Resource
    The pathobiology of salivary gland (1992)
    Springer
    Virchows Archiv 421 (1992), S. 105-113 
    Details
    ISSN: 1432-2307
    Keywords: Parotid gland ; ras ; Transgenic mouse ; Electron microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01607042
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  • 6
    Electronic Resource
    Electronic Resource
    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
    Keywords: Silver staining ; Paired helical filaments ; Cerebral amyloid ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01600257
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  • 7
    Electronic Resource
    Electronic Resource
    Malignant paraganglioma of the uterus (1992)
    Springer
    Virchows Archiv 420 (1992), S. 453-457 
    Details
    ISSN: 1432-2307
    Keywords: Uterus ; Paraganglioma ; Intracytoplasmic hyaline globules ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01600518
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  • 8
    Electronic Resource
    Electronic Resource
    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
    Keywords: Peripheral neuropathy ; Cryoglobulinemia ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00713536
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  • 9
    Electronic Resource
    Electronic Resource
    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
    Keywords: Progressive supranuclear palsy ; Neurofibrillary tangles ; Pick body ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00311384
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  • 10
    Electronic Resource
    Electronic Resource
    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
    Keywords: Localized hypertrophic neuropathy ; Electron microscopy ; Immunohistochemistry ; Nerve growth factor receptor ; Schwann cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00310035
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  • 11
    Electronic Resource
    Electronic Resource
    Immunohistochemistry of cholinergic receptors (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 407-429 
    Details
    ISSN: 1432-0568
    Keywords: Acetylcholine receptors ; Immunocytochemistry ; Electron microscopy ; Human motor endplate ; Human cerebral cortex ; Neurodegenerative disorders
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185457
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  • 12
    Electronic Resource
    Electronic Resource
    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
    Keywords: Dorsal tegmental nucleus of Gudden ; Laterodorsal tegmental nucleus ; Synaptic organization ; Anterograde tracing study ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185614
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  • 13
    Electronic Resource
    Electronic Resource
    Neuronal autophagic vacuoles in experimental scrapie and Creutzfeldt-Jakob disease (1992)
    Springer
    Acta neuropathologica 83 (1992), S. 134-139 
    Details
    ISSN: 1432-0533
    Keywords: Scrapie ; Creutzfeldt-Jakob disease ; Neuronal autophagy ; Neuropathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00308472
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  • 14
    Electronic Resource
    Electronic Resource
    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
    Keywords: Alzheimer's disease ; Astrocytes ; Electron microscopy ; Immunohistochemistry ; Paired helical filaments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296783
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  • 15
    Electronic Resource
    Electronic Resource
    Retinal photoreceptor fine structure in the velvet cichlid (Astronotus ocellatus) (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 363-370 
    Details
    ISSN: 1432-0568
    Keywords: Retinal photoreceptors ; Electron microscopy ; Teleost ; Astronatus ocellatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185986
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  • 16
    Electronic Resource
    Electronic Resource
    Intraventricular infusion of N-methyl-D-aspartate (1992)
    Springer
    Acta neuropathologica 84 (1992), S. 630-637 
    Details
    ISSN: 1432-0533
    Keywords: Dentrites ; Excitotoxicity ; Glutamate ; N-Methyl-d-aspartate ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227740
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  • 17
    Electronic Resource
    Electronic Resource
    Intraventricular infusion of N-methyl-d-aspartate (1992)
    Springer
    Acta neuropathologica 84 (1992), S. 621-629 
    Details
    ISSN: 1432-0533
    Keywords: Blood-brain barrier ; Endothelium ; Excitotoxicity ; N-Methyl-d-aspartate ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227739
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  • 18
    Electronic Resource
    Electronic Resource
    Increased iron content in the putamen of patients with striatonigral degeneration (1992)
    Springer
    Acta neuropathologica 84 (1992), S. 328-330 
    Details
    ISSN: 1432-0533
    Keywords: Striatonigral degeneration ; Putaminal pigment ; Iron ; Atomic absorption spectroscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227827
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  • 19
    Electronic Resource
    Electronic Resource
    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
    Keywords: Histiocytic markers ; Astrocytoma ; Electron microscopy ; Glial fibrillary acidic protein ; Granular cell tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227746
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  • 20
    Electronic Resource
    Electronic Resource
    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
    Keywords: Retinal pigment epithelium (RPE) ; Electron microscopy ; Teleost ; Astronatus ocellatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185987
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  • 21
    Electronic Resource
    Electronic Resource
    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
    Keywords: Intestine ; Interstitial cells ; Innervation ; Electron microscopy ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186974
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  • 22
    Electronic Resource
    Electronic Resource
    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
    Keywords: Cepharanthine ; Minoxidil ; Culture ; Hair cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00372583
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  • 23
    Electronic Resource
    Electronic Resource
    Ultrastructural localization of actin in normal human skin (1992)
    Springer
    Archives of dermatological research 284 (1992), S. 242-245 
    Details
    ISSN: 1432-069X
    Keywords: Immunogold ; Electron microscopy ; Human skin ; Actin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00375802
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  • 24
    Electronic Resource
    Electronic Resource
    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
    Keywords: Hair follicle ; Basal lamina ; Dermal papilla cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00372585
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  • 25
    Electronic Resource
    Electronic Resource
    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
    Keywords: Catheter ; Electron microscopy ; Infection ; Adherence ; Candida albicans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01708582
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  • 26
    Electronic Resource
    Electronic Resource
    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
    Keywords: Immunocytochemistry ; Visual pathways ; Electron microscopy ; Hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229008
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  • 27
    Electronic Resource
    Electronic Resource
    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
    Keywords: Bradyrhizobium ; Electron microscopy ; Glycine (root nodules) ; High-pressure freezing ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216809
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  • 28
    Electronic Resource
    Electronic Resource
    Studies on the hepatotoxicity induced by bis (tributyltin) oxide (1992)
    Springer
    Archives of toxicology 66 (1992), S. 182-187 
    Details
    ISSN: 1432-0738
    Keywords: Bis(tributyltin) oxide ; Liver ; Electron microscopy ; X-ray microanalysis ; Biochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01974012
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  • 29
    Electronic Resource
    Electronic Resource
    Dynamics of PhiX174 protein E-mediated lysis of Escherichia coli (1992)
    Springer
    Archives of microbiology 157 (1992), S. 381-388 
    Details
    ISSN: 1432-072X
    Keywords: PhiX174 ; Bacterial lysis ; Escherichia coli ; Electron microscopy ; Membranes ; Cell envelope
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00248685
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  • 30
    Electronic Resource
    Electronic Resource
    Age-related immunoreactivity pattern in medulloblastoma (1992)
    Springer
    Child's nervous system 8 (1992), S. 326-331 
    Details
    ISSN: 1433-0350
    Keywords: Medulloblastomas ; Immunohistochemistry ; Cytokeratins ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296563
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  • 31
    Electronic Resource
    Electronic Resource
    The human placental transferrin receptor: Reconstitution into liposomes and electron microscopy (1992)
    Springer
    Bioscience reports 12 (1992), S. 471-482 
    Details
    ISSN: 1573-4935
    Keywords: Transferrin ; Receptor ; Isolation ; Reconstitution ; Liposomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01122035
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  • 32
    Electronic Resource
    Electronic Resource
    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
    Keywords: Electron microscopy ; secretion ; neuropeptides ; exocytosis ; endocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: 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.
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    URL: http://dx.doi.org/10.1007/BF01122037
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  • 33
    Electronic Resource
    Electronic Resource
    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
    Keywords: Haloperidol ; Clozapine ; Perforated synapses ; Electron microscopy ; Tardive dyskinesia ; Extrapyramidal syndrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02253587
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  • 34
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    Electronic Resource
    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
    Keywords: Chordotonal organ ; Scolopidium ; Homology ; Electron microscopy ; Sensilla ; Evolution ; Actias luna (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319368
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  • 35
    Electronic Resource
    Electronic Resource
    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
    Keywords: Retina ; Dopaminergic neurons ; Synapses ; Inner plexiform layer ; Immunocytochemistry ; Electron microscopy ; Bufo marinus (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
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    URL: http://dx.doi.org/10.1007/BF00319375
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  • 36
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    Electronic Resource
    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
    Keywords: Regeneration ; Skeletal muscle ; Injury ; Autoradiography ; Morphometry ; Electron microscopy ; Mouse (SJL/J BALB/c)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384736
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    Electronic Resource
    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
    Keywords: Enkephalins ; Neuropeptides ; Neurohemal organ ; Immunogold ; Electron microscopy ; Carcinus maenas, Uca pugilator, Eriocheir sinensis (Crustacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00645054
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  • 38
    Electronic Resource
    Electronic Resource
    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
    Keywords: Basic fibroblast growth factor ; Regeneration ; Degeneration ; Immunohistochemistry ; Electron microscopy ; Masseter muscle ; Myoneural junction ; Mouse (dystrophic mdx)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00645060
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  • 39
    Electronic Resource
    Electronic Resource
    Ovarian innervation develops before initiation of folliculogenesis in the rat (1992)
    Springer
    Cell & tissue research 270 (1992), S. 87-93 
    Details
    ISSN: 1432-0878
    Keywords: Ovarian nerves ; Development ; Folliculogenesis ; Tyrosine hydroxylase ; Immunohistochemistry ; Electron microscopy ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00381883
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  • 40
    Electronic Resource
    Electronic Resource
    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
    Keywords: Adrenal cortex ; Ageing ; Steroidogenesis ; Electron microscopy ; Morphometry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328012
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  • 41
    Electronic Resource
    Electronic Resource
    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
    Keywords: Macrophages ; Small intestine ; Large intestine ; External muscle layer ; Immunohistochemistry ; Histochemistry ; Electron microscopy ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00328013
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  • 42
    Electronic Resource
    Electronic Resource
    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
    Keywords: Teeth ; Cementum ; Cementoblasts ; Matrix production ; Electron microscopy ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302971
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  • 43
    Electronic Resource
    Electronic Resource
    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
    Keywords: Leydig cells ; Macrophages ; Development, ontogenic ; Electron microscopy ; Testis ; (Rat Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302977
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  • 44
    Electronic Resource
    Electronic Resource
    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
    Keywords: Intestine ; Interstitial cells ; Pacemaker ; Electron microscopy ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318788
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  • 45
    Electronic Resource
    Electronic Resource
    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
    Keywords: Urinary bladder ; Epithelial desquamation ; TPA ; Electron microscopy ; Rat (Donryu)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318792
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  • 46
    Electronic Resource
    Electronic Resource
    Histochemical localization of nucleoside triphosphatase activity in assimilate conducting plant tissue (1992)
    Springer
    Protoplasma 167 (1992), S. 145-151 
    Details
    ISSN: 1615-6102
    Keywords: ATPase ; UTPase ; Electron microscopy ; Energy-dispersive X-ray microanalysis ; Gomphrena globosa ; Histochemistry ; Hordeum distichon ; Monstera deliciosa ; Phloem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403377
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  • 47
    Electronic Resource
    Electronic Resource
    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
    Keywords: Cochlea-Stria vascularis ; Electron microscopy ; Endocochlear potential ; Loop diuretics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00183494
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  • 48
    Electronic Resource
    Electronic Resource
    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
    Keywords: Cricopharyngeal dysphagia ; Muscle biopsy ; Electron microscopy ; Enzyme histochemistry ; Myositis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00178473
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  • 49
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    Electronic Resource
    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
    Keywords: Inner ear ; Rat spiral limbus ; Intercellular matrix ; Electron microscopy ; Immunomorphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00178474
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  • 50
    Electronic Resource
    Electronic Resource
    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
    Keywords: Nerve endings ; Outer hair cells ; Acoustic exposure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00714495
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  • 51
    Electronic Resource
    Electronic Resource
    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
    Keywords: Corticotropin releasing hormone ; Adrenal gland ; Mitochondria ; Sprague-Dawley rat ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: 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.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092340212
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  • 52
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    Electronic Resource
    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
    Keywords: Anatomy and histology ; Basement membrane ; Collagen ; Connective tissue ; Elastic tissue ; Electron microscopy ; Rats ; Submandibular gland ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: 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.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092340305
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    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
    Keywords: Blood cells ; Teleosts ; Gilthead seabream ; Sparus aurata ; Light microscopy ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: 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.
    Additional Material: 21 Ill.
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    URL: http://dx.doi.org/10.1002/ar.1092340203
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    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
    Keywords: Blastocyst ; Pre-implantation ; EGF ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: 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.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/mrd.1080320308
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    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
    Keywords: Electron microscopy ; Autoradiography ; Maximum-likelihood estimation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200108
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    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
    Keywords: Electron microscopy ; Scanning electron microscopy ; High resolution ; Cytoskeleton ; Biological specimen preparation ; Cultured cells ; Electrophoresis ; Bifunctional crosslinking reagents ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
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    URL: http://dx.doi.org/10.1002/jemt.1070220203
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    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
    Keywords: 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
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210409
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    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
    Keywords: Quantitative morphology ; Morphometry ; Light microscopy ; Electron microscopy ; PCS System III ; MS-DOS ; UNIX ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070210410
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    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
    Keywords: Identified neurons ; Quantification ; Rotating/tilting ; Synaptic contacts ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230408
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    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
    Keywords: Electron microscopy ; Evolution ; Flatworms ; Nematodes ; Nervous system ; Review ; Sense organs ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 26 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070220306
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    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
    Keywords: Cilia ; Microvilli ; Ultrastructure ; Electron microscopy ; Evolution ; Cladistics ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
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    URL: http://dx.doi.org/10.1002/jemt.1070230102
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    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
    Keywords: Sensory ; Chemosensory ; Ultrastructure ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
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    URL: http://dx.doi.org/10.1002/jemt.1070220402
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    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
    Keywords: Sensilla ; Electron microscopy ; Sexual dimorphism ; Homology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
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    URL: http://dx.doi.org/10.1002/jemt.1070220403
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    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
    Keywords: Olfactory chemoreceptors ; Electron microscopy ; Wall structures ; Sheath cells ; Dendrites ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
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    URL: http://dx.doi.org/10.1002/jemt.1070220406
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    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
    Keywords: Electron microscopy ; Endocrine neoplasm ; Pituitary adenomas ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 36 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070200202
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    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
    Keywords: Pinealocyte ; Pineal-neuron ; Synapses ; Ribbon synapse ; Innervation ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
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    URL: http://dx.doi.org/10.1002/jemt.1070210205
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    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
    Keywords: Accessory olfactory ; Nasal glands ; Odorant binding protein ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
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    URL: http://dx.doi.org/10.1002/jemt.1070230108
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    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
    Keywords: CNS ; Light microscopy ; Electron microscopy ; Cerebral cortex ; Nerve cell ; Impregnation method ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 38 Ill.
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    URL: http://dx.doi.org/10.1002/jemt.1070230403
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    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
    Keywords: Electron microscopy ; Water ; Image analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070210308
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    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
    Keywords: Stereology ; Software ; Coordinate geometry ; Volume density, Surface density ; Numerical density ; Serial sections ; Light microscopy ; Electron microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Natural Sciences in General
    Notes: 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.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jemt.1070210403
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    Scanning and transmission electron microscopy evidence of the cytological effect of pyrrolnitrin on ‘Microsporon audouinii’ Gruby CBS 313-54 ‘in vitro’ (1974)
    Springer
    Mycopathologia 53 (1974), S. 111-123 
    Details
    ISSN: 1573-0832
    Keywords: Microsporon audouinii ; Pyrrolnitrin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Scanning and transmission electron microscopy showed that a ceiling quantity (1.56 mcg) of antifungal antibiotic Pyrrolnitrin caused heavy damage to dermathophyteMicrosporon audouinii Gruby CBS 313-54in vitro. Suitable preparation technique made it clear that the changes involved consisted of hyphal collapse on the edge of the culture, with loss of euplasmic organelles identity and cell autolysis. The cell wall, however, was apparently undamaged. These findings fit in with the suggestion that the mode of action of the antibiotic leads to generalised lipoproteic membranes damage. They must, however, be considered as representing the result of the terminal phase of cell distress.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02127201
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    Morphodynamik der C-Zellen der Schilddrüse und der Parathyreoideazellen der Ratte nach ein- bis achtwöchiger Calcitoninbehandlung (1974)
    Springer
    Anatomy and embryology 144 (1974), S. 19-38 
    Details
    ISSN: 1432-0568
    Keywords: Calcitonin ; C-Cells of the thyroid and cells of the parathyroid glands ; Secondary hyperparathyroidism ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Im Verlauf ein- bis achtwöchiger Behandlung von Wistar-Ratten mit täglich 300 mMRC Einheiten Schweinecalcitonin kam es in den C-Zellen der Schilddrüse, verglichen mit denen der Kontrollserien (unbehandelte und mit Acetatpuffer allein behandelte Tiere), einerseits zu einer morphometrisch signifikanten Abahme der Zahl der Sekretgranula, während andererseits sämtliche Zellorganellen (Mitochondrie,, Golgi-Apparat und auch das granuläre endoplasmatische Reticulum) besser entwickelt waren. In den in gleichen Zeitabschnitten untersuchten Parathyroideazellen fanden wir bei mit Calcitonin behandelten Ratten Strukturveränderungen, die auf eine erhöhte Aktivität hinwiesen: Einfaltungen des Kerns, Erweiterung der Intercellularräume mit Vermehrung und Verlängerung der in diese hineinragenden Mikrovilli, bessere Ausbildung des Golgi-Apparates und des granulären endoplasmatischen Reticulums sowie eine größere Menge freier Ribosomen. Die Zahl der Sekretgranula war eindeutig höher als bei den Kontrolltieren. Der Ca ++- und Mg++-Blutspiegel zeigte während der ganzen Versuchsdauer bei allen Tieren keine statistisch faßbaren Änderungen. Die Autoren vertreten die Hypothese, daß die Aktivierung der C-Zellen durch das Auftreten eines durch die Calcitoninverabreichung hervorgerufenen sekundären Hyperparathyroidismus zustande kommt.
    Notes: Summary Male Wistar rats were injected for one to eight weeks with 300 mMRC units per day of porcine calcitonin. During this period C-cells (or “parafollicular” cells) of the thyroid gland and cells of the parathyroid glands were examined ultrastructurally. The C-cells were further studied morphometrically in animals treated with calcitonin dissolved in acetate buffer as well as in acetate buffer- and not-treated control animals. In the thyroid C cells the number of secretion granules significantly decreased following calcitonin administration, whereas the volume of all cell organelles (mitochondria, Golgi complex and granular endoplasmic reticulum) augmented. The cells of the parathyroid glands of the calcitonin-treated rats showed structural changes due to higher activity: invaginations of the nuclear envelope, enlargement of the intercellular spaces with increase in number and size of the microvilli, better development of the Golgi complex and the granular endoplasmic reticulum, larger population of free ribosomes and secretory granules. However, no significant differences in the blood calcium and magnesium levels were detected when a comparison was made of calcitonin-treated and control animals. All these observations support the hypothesis that the activation of the C-cells may result from a secondary hyperparathyroidism itself induced by the administration of moderate doses of calcitonin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00518631
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    Isolation of sarcolemma from human skeletal muscle (1974)
    Springer
    Anatomy and embryology 145 (1974), S. 187-196 
    Details
    ISSN: 1432-0568
    Keywords: Human skeletal muscle ; Sarcolemma ; Isolation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An isolation procedure for sarcolemma of human skeletal muscle is described. The method includes the possibility to prepare sarcoplasmic reticulum from the same muscle fibres. Electron microscopy reveals a homogeneous final fraction of 80–90% myofibre enveloping membranes contaminated by blood vessel membranes. The typical three-laminar composition of isolated sarcolemma is demonstrated. The mechanism of muscle fibre emptying is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00519728
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  • 74
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    Zur Feinstruktur des Maulwurfovars (Talpa europaea, L.) (1974)
    Springer
    Anatomy and embryology 144 (1974), S. 1-18 
    Details
    ISSN: 1432-0568
    Keywords: Mammals ; Mole ; Ovary ; Interstitial cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Ovar des Maulwurfs wurde licht- und elektronenmikroskopisch untersucht. Der Feinbau der verschiedenen Follikel und der Keimzellen entspricht dem anderer Species. Die Granulosa wird vermutlich erst mit der Ovulation luteinisiert. Sie enthält reichlich rauhes endoplasmatisches Reticulum und Sprossen von glattem endoplasmatischem Reticulum. Die Zellen der Theka interna leiten sich von Fibrocyten ab und enthalten neben reichlich glattem ER auch granuläres ER sowie Lipidtropfen und Mitochondrien mit Cristae und Tubuli. Diese Zellen ähneln in ihrer Feinstruktur stark den Zwischenzellen des ovarialen Marks. Dieses enthält in der Marksträngen Epithelien, die einer kräftigen Basalmembran aufsitzen. Sie werden teils als embryonal persistierende Vorstufen von Granulosa- oder Sertoli-Zellen, teils als Granulosasprossen aus der Rinde gedeutet. Für die Zwischenzellen des Marks erscheint eine Analogie mit den Hiluszellen des menschlichen Ovarialmarks bzw. eine Homologie mit den Leydig-Zellen des Hodens zweifelhaft. Als mögliche Quelle für diesen Zelltyp werden neben embryonal liegengebliebenen Anteilen auch Thekakeile und Epoophoronzellen sowie Fibroblasten diskutiert. Neben einer Steroid-synthese dürfte ihnen eine Reserve- und Speicherfunktion zukommen.
    Notes: Summary In order to make possible comparison between relatively primitive and relatively specialized gonads, the ovary of the mole was studied by light and electron microscopy. The ultrastructure of primary, secondary and tertiary follicles and of the germ cells is similar to that of other species. The granulosa cells of secondary and early tertiary follicles contain abundant rough endoplasmic reticulum and a small number profiles of smooth endoplasmic reticulum. The cells of the theca interna, which develop from simple fibrocytes are rich in smooth and rough endoplasmic reticulum and contain many lipid droplets and mitochondria, which possess both cristae and tubuli mitochondriales. At the time of ovulation, the granulosa cells are luteinized and their ultrastructure changes correspondingly. The medulla of the ovary is composed of the medullary cords and the interstitial cells. The medullary cords are solid epithelial cords, which are surrounded by a prominent basement membrane. They may be derived from embryonic precursors of granulosa—or Sertoli-cells or bud from the cortical zonae granulosae. There is a striking morphological similarity between the theca and interstitial cells. The interstitial cells of the ovarian medulla differ from the hilus cells of the human ovary and the Leydig-cells of the testis. They may develop either from embryonic rudiments of Leydig—or hilus-cell precursors, or bud from the theca or the epoophoron, or they may develop from fibrocytes. In addition to their suggested activity in steroid biosynthesis, the interstitial cells may have a trophic or storage function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00518630
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    Ultrastructural differences along the colonic mucosa of the mouse (1974)
    Springer
    Anatomy and embryology 144 (1974), S. 75-83 
    Details
    ISSN: 1432-0568
    Keywords: Colonic mucosa ; Mouse ; Vacuolated cells ; Electron microscopy ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Swiss ICR adult male mice were used to analyse regional morphologic differences in the mucosa of the colon. The three cell types recently described in the descending colon of the mouse were also observed in the transverse and in the ascending colon. However the vacuolated cells of the crypts have presented different morphological characteristics depending on their localisation. In the ascending colon, they exhibited small supranuclear vesicles in contrast to the large vesicles observed in the descending colon. Several cell combining features of argentaffin-vacuolated, goblet-vacuolated and goblet-argentaffin cells have been observed. Furthermore a special type of granule referred to as a secondary lysosome was observed in the peripheral area of the typical goblet cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00518634
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    Electron microscopic observations on postnatal development of the X zone in mouse adrenal cortex (1974)
    Springer
    Anatomy and embryology 144 (1974), S. 85-100 
    Details
    ISSN: 1432-0568
    Keywords: X zone ; Electron microscopy ; Development ; Adrenal ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The postnatal development and involution of the X zone in the mouse adrenal cortex of both sexes were examined using the light and electron microscopes. At 0–5 days of age, no special cell group could be distinguished for the developing X zone in the inner cortex. The inner cortical cells contained spherical or ellipsoidal mitochondria with vesiculotubular cristae, vesiculotubular smooth endoplasmic reticulum (sER) and electron-lucent lipid droplets. The first sign of the developing X zone was the appearance of small groups of cells in juxtamedullary region differing from the cells in other part of inner cortex at 8 days. The electron microscopy showed that such cells contained nuclei of somewhat irregular outline and some parallel stacks of flattened sER. At 10–11 days, a thin layer of small eosinophilic cells were clearly identified as the developing X zone light microscopically in both sexes. Electron microscopically, the X zone cells showed a much dense cytoplas, which contained abundant sER, many mitochondria and numerous ribosomes. The typical X zone cells were characterized by the formation of peculiar mitochondrial complexes and whorled pattern of the sER. Mitoses were often found in the X zone, where mitotic cells even contained the whorled sER and bizarre mitochondria characteristic of the typical X zone cells. In the male the X zone rapidly involuted and might disappear by 30 days of age, whereas in the female X zone persisted as a thicker layer with the earlist sign of fatty degeneration. The origin of the X zone cell and the process of formation of its characteristic organelles are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00518635
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    Ultrastructure of gonadal ridge in male and female pig embryos (1974)
    Springer
    Anatomy and embryology 147 (1974), S. 19-34 
    Details
    ISSN: 1432-0568
    Keywords: Gonads/embryology ; Swine/embryology ; Sex determination ; Electron microscopy ; Sex characteristics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pig embryos aged 21–22 days (d) were obtained from artificially inseminated sows for an ultrastructural study of the development and sex differentiation of the gonadal ridge. The chromosomal sex of the embryos was identified by a chromosome analysis. At the age of 21 d the gonadal ridge consisted of three different tissue: the surface epithelium, the primitive cords, and the mesenchyme. The surface epithelial cells contained elongate mitochondria with lamellar cristae, granular endoplasmic reticulum (GER), the Golgi complex, free polysomes, coated vesicles and fine filaments. The epithelium was continuous with the primitive cords, which were composed of ultrastructurally similar cells. The epithelial basal lamina followed the cord surface, but covered it incompletely. Primordial germ cells (PGC) were located under the surface epithelium in the mesenchyme and in the cords. The nucleus with a prominent nucleolus, and the large mitochondria were round. The cytoplasm contained a pair of centrioles, the Golgi complex, solitary lamellae of the GER, free polysomes, lipid droplets and some coated vesicles. The PGC entered the gonadal cords before these were surrounded by the continuous basal lamina. A day later (22 d) the number and length of the cords were increased. The PGC were more frequent and seen also in deeper layers. All the structures studied at the age of 21–22 d showed that the gonadal ridge also at the ultrastructural level is at the sexually indifferent stage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317961
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    The fine structure of the pulmonary stretch receptor in the rat (1974)
    Springer
    Anatomy and embryology 143 (1974), S. 215-222 
    Details
    ISSN: 1432-0568
    Keywords: Lung ; Stretch receptors ; Light microscopy ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Lappenbronchien (3./6.) (Durchmesser bei mittlerer Inspirationslage 500–700 μ) von männlichen und weiblichen Wistarratten wurden licht- und elektronenmikroskopisch untersucht. Diese Bronchien entsprechen im Wandbau den mittleren Bronchioli größerer Säugetiere. Freie, verzweigte lanzettförmige Terminalfasern werden im Bindegewebe der lamina propria beschrieben. Sie sind in das elastisch muskuläre System der Bronchuswand eingebaut. Die zugehörige markhaltige afferente Nervenfaser ist verzweigt und hat einen Durchmesser von 4–6 μ. Außerdem werden efferente motorische Endigungen an der glatten Bronchialmuskulatur beschrieben. Die freien lanzettförmigen und verzweigten Terminalfasern sind möglicherweise Dehnungsrezeptoren für den Hering Breuer Reflex.
    Notes: Summary In rats the 3rd to 6th bronchi, measuring 500–700 μ in diameter during inspiration, were investigated by light and electron microscopy. The histological appearance of these bronchi is comparable to that of medium sized bronchioles of larger animals. The branched and lanceolate terminals are associated with the connective tissue of the lamina propria and the smooth muscle cell layer. In this way the terminals are bound to the myoelastic system of the bronchial wall. The myelinated afferent fiber is branched and the diameter measures about 4–6 microns. Besides afferent nerve terminals these are numerous efferent endings on the smooth muscle basement laminae. It is supposed that the described receptor represents the pulmonary stretch receptor of the Hering Breuer reflex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00525771
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    Cerebellar projections to the nuclei ventralis lateralis and ventralis anterior thalami (1974)
    Springer
    Anatomy and embryology 146 (1974), S. 95-111 
    Details
    ISSN: 1432-0568
    Keywords: Cerebellum ; Thalamus ; Electron microscopy ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An experimental electron microscopical study has been made on the mode of termination of the cerebellothalamic projections in the cat. Supporting experimental light microscopical studies of silver impregnated sections following a large lesion of the cerebellar nuclei and light microscopical autoradiographic studies of the thalamus following injections of tritiated leucine in parts of the cerebellar nuclei, have been made as well. Following large lesions of the cerebellar nuclei, only the largest occuring type of bouton in the cat's VL and VA (type LR bouton) degenerates. Following such lesions, type LR boutons undergo a filamentous hypertrophy before becoming electrondense. One degenerating LR bouton establishes complex synapses with the dendrites of both thalamocortical relay cells and interneurons. Not all type LR boutons in VL and VA degenerate following lesions of the cerebellar nuclei. Light microscopical autoradiographic studies as well as experimental electron microscopical investigations indicate that cerebellothalamic fibers end in clusters within VL and VA, and that the areas of termination lie more rostrally within these thalamic nuclei than has been inferred from experimental studies of silver impregnated sections following lesions of the cerebellar nuclei. The findings are discussed with respect to relevant morphological and physiological data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341384
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    Studies on dentinogenesis in the rat (1974)
    Springer
    Calcified tissue international 16 (1974), S. 93-107 
    Details
    ISSN: 1432-0827
    Keywords: Dentinogenesis ; Globules ; Pyrophosphatase ; Calcification ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Three-day-old rats were fixed by perfusion with glutaraldehyde and thin slices were cut of the first molar germs. The slices were treated with EDTA and “activated” with buffered solutions containing Mg2+, Ca2+ or Zn2+. Incubation was carried out in buffered solutions (pH 8.5) containing inorganic pyrophosphate and Pb2+. In the Mg2+-activated specimens incubation products were localized to the plasma membranes in the stratum intermedium and the subodontoblastic area. Lead deposits were found on the periphery of the dentinal globules. Incubation products were more randomly distributed in Ca2+-activated specimens whereas those activated with Zn2+ displayed a deposition of lead precipitates mainly corresponding to that seen after activation with Mg2+. The findings are discussed in reference to the localization of alkaline phosphatase in the dentin-producing tissues and it is proposed that the results are indicative of the presence of an inorganic pyrophosphatase in these tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02008216
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    Acid phosphatase in the mantle of the shell-regenerating snailHelisoma duryi duryi (1974)
    Springer
    Calcified tissue international 15 (1974), S. 213-220 
    Details
    ISSN: 1432-0827
    Keywords: Acid phosphatase ; Electron microscopy ; Shell Regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Acid phosphatase activity was mainly localized in the lysosomes in all the regions of the outer epithelium. The transitional portion of the outer epithelium showed more intense activity than the other regions. During shell regeneration the activity of this portion decreased to a minimum level at 12 hours and was restored to normal at 72 hours. The other regions showed no change of activity during shell regeneration. It is postulated that the acid phosphatase in the transitional protion is responsible for conferring calcifiability to the organic matrix of the shell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02059058
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    Bleivergiftung: Feinstrukturelle Lokalisation von Blei im Gingivagewebe (1974)
    Springer
    International archives of occupational and environmental health 32 (1974), S. 129-144 
    Details
    ISSN: 1432-1246
    Keywords: Lead intoxication ; Lead line ; Electron microscopy ; Stomato-Logy ; Bleiintoxikation ; Bleisaum ; Elektronenmikroskopie ; Stomatologie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die histologischen Befunde beim Bleisaum im Licht- und Dunkelfeld werden kurz besprochen. Die Beobachtungen stimmen mit den bekannten Angaben aus der Literatur überein. Elektronenmikroskopische Untersuchungen an Gingivabiopsien von 3 Patienten mit Bleivergiftung und deutlichem Bleisaum zeigten, daß die Ablagerungen sowohl extra- als auch intracellulär zu finden sind. Extracelluläres Blei war hauptsächlich zwischen kollagenen Pasern, um die Blutgefäße und in die Basallamina an der dermo-epidermalen Grenze eingelagert. Intracelluläres Blei war in einer Gruppe von Zellen in membranbegrenzten Phagosomen vorhanden, während es in anderen Zellen diffus im Cytoplasma verteilt war, wobei es zu einer Einlagerung in die verschiedenen cytoplasmatischen Membransysteme, besonders in die mitochondrialen Membranen, kam. Reste von lytischen Zellen mit diffus im Cytoplasma verteiltem Metall wurden von Makrophagen aufgenommen. Es wird vermutet, daß ein Cyclus abläuft, der mit der Phagocytose von Blei beginnt und über progrediente Zellschädigung zur Lyse führt. Die Ergebnisse werden mit Beobachtungen bei Argyrose verglichen. Das unterschiedliche Verteilungsmuster der Metalle bei diesen beiden Erkrankungen wird im Hinblick auf eine Hypothese über den Pathomechanismus von Schwermetallvergiftungen diskutiert.
    Notes: Summary The histology of the lead line is briefly reviewed on the basis of light- and dark-field microscope studies. The observations correspond with published data. Electron microscope studies on gingival biopsies obtained from 3 patients with lead intoxication and marked lead lines showed extra- and intracellular deposits of the metal. Extracellular lead was preferentially deposited between collagen fibers, around blood vessels and on the basal lamina of the dermal-epidermal junction. Intracellular lead was present within membrane-bound phagosomes of one group of cells, whereas it was diffusely distributed within the cytoplasm of another cell group. In the latter it was deposited on the different cytoplasmic membrane systems, particularly on the mitochondrial membranes. Residues of lytic cells, which contained diffusely distributed metal, were phagocytized by macrophages. It is assumed that a cycle starts with the phagocytosis of lead and ends with increasing cellular damage and cytolysis. The results are compared with the observations in argyria. The different distribution patterns of the metal in the two diseases are discussed in the light of a proposed hypothesis on the pathomechanisms of heavy-metal poisoning.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00539101
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    Early structural changes in a case of late infantile amaurotic idiocy (early form of Batten-Spielmeyer-Vogt disease) (1974)
    Springer
    Journal of neurology 207 (1974), S. 271-278 
    Details
    ISSN: 1432-1459
    Keywords: Amaurotic Idiocy ; Late infantile Neuronal ceroid-lipofuscinosis ; Mental retardation ; Electron microscopy ; Inclusion bodies ; Membrane bound neuronal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es werden die lichtmikroskopischen, histochemischen und elektronenmikroskopischen Befunde in der Gehirnbiopsie eines Frühfalles von später infantiler Form der amaurotischen Idiotie (oder einer frühen Form der Batten-Spielmeyer-Vogt-Krankheit) beschrieben. An die Membranen gebundene cytoplasmatische Einschlußkörperchen sind in einigen wenigen Neuronen vorhanden. Die morphologischen Befunde werden mit Bezug auf die Ätiologie der Erkrankung diskutiert.
    Notes: Summary The light microscopic, histochemical and electron microscopic findings in a brain biopsy of an early case of Late Infantile Amaurotic Idioty (early form of Batten-Spielmeyer-Vogt disease) are reported. Membrane bound cytoplasmic inclusion bodies are present in a small number of neurons. The morphological findings are discussed in relation to the etiology of the disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312581
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  • 84
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    Electronic Resource
    Central neuroblastoma induced by transplacental administration of methylnitrosourea in Wistar-R rats (1974)
    Springer
    Journal of neurology 208 (1974), S. 1-16 
    Details
    ISSN: 1432-1459
    Keywords: Neuroblastoma, central ; N-methyl-N-nitrosourea ; Transplacentar carcinogenesis ; Neuronal differentiation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die transplacentare Gabe von MNH an schwangere Ratten am 16. Tage der Gravidität, obwohl sie bei allen untersuchten Nachkommen zu Gehirnmißbildungen führte, erzeugte nur einen Tumor des Nervensystems. Dieser bösartige Tumor, bei dem am Lichtmikroskop die Diagnose Neuroblastoma gestellt wurde, wurde auch durch E.M. untersucht. Obwohl Strukturen stark andeutend auf unreife oder regressive synapsenartige Kontakte vorhanden waren, konnten gutentwickelte Synapsen jedoch nicht beobachtet werden. Bei den verschiedenen neuronalen Eigenschaften, die bei den Tumorzellen zum Vorschein kamen, besonders extensive Nissl-Schollen und zahlreiche „subsurface“ Zisternen, waren mehrere typisch für die embryonale Entwicklung der Nervenzellen: geästete Zellfortsätze mit Wachstumskonen und dense core, neurosekretorische Granula; diese Granula wurde als charakteristisch für neuerwachsende Nervenfasern angesehen. Die Anwesenheit dieser Entwicklungsmerkmale in einem Nervenzellenmalignom kann die vermutete embryonale Abstammung des Neuroblastomas als Abkömmling von unreifen Formen und nicht von entdifferenzierten Zellen bestätigen.
    Notes: Summary Transplacentar administration of MNU to pregnant Wistar-R rats at the 16th day of gestation, while inducing cerebral malformations in all the offspring examined, produced only one nervous system tumor. This malignant neoplasm, diagnosed optically as a neuroblastoma, was also examined at the EM level. Although structures strongly suggestive of incipient or abortive synaptic formations were present, well developed synapses were not observed. Among the various neuronal features displayed by the tumor cells, notably some extensive Nissl arrays and numerous subsurface cisternae, several were indicative of maturing nerve cells: branching tumoral processes provided with typical growth cones and dense cored “neurosecretory” vesicles. These vesicles are now considered to be one of the characteristics of newly developing nerve fibers. The presence of these developmental features in a nerve cell tumor helps to substantiate the embryonic origin of neuroblastomas postulated as arising from immature forms and not from dedifferentiated cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00313329
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  • 85
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    Electronic Resource
    The ninth retinula cell in the ommatidium of the worker honey bee (Apis mellifica L.) (1974)
    Springer
    Cell & tissue research 147 (1974), S. 589-593 
    Details
    ISSN: 1432-0878
    Keywords: Ommatidium ; Apis mellifica ; Ninth retinula cell ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Rhabdom im Ommatidium der Arbeitsbiene wird von 9 Retinulazellen aufgebaut. Die exzentrische Zelle = Zelle Nr. 9 (ca. 50–75 μ lang) liegt im distalen Bereich des Ommatidiums, unterhalb der Zelle Nr. 4 (nach Varela und Porter, 1969), die ihrerseits den Rhabdomverband verläßt und als Axon zur Basalmembran zieht.
    Notes: Summary The rhabdom in the ommatidium of the worker honey bee is built up of 9 retinula cells. The eccentric cell = cell No. 9 (approx. 50–75 μ long) is situated in the distal region of the ommatidium beneath the fourth cell (numbered according to Varela and Porter, 1969), which in its turn leaves the rhabdom and runs as an axon towards the basement membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307257
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  • 86
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    Electronic Resource
    Ciliogenesis and ciliary anomalies in thymic cysts of “nude” mice (1974)
    Springer
    Cell & tissue research 148 (1974), S. 397-406 
    Details
    ISSN: 1432-0878
    Keywords: Thymus ; “Nude” mouse ; Ciliogenesis ; Ciliary anomalies ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The thymus of the “nude” mouse is composed of ciliated cysts. In the adult mouse, different steps of ciliogenesis can be observed. The ciliated cells exhibit several anomalies in the centriole and in the cilium itself; the most important ones are the half-centriole and the compound cilia. An explanation for the occurrence of frequent anomalies in ciliated cells is suggested. Finally, some single cilia are described in fat cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224266
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  • 87
    Electronic Resource
    Electronic Resource
    Further observations on urethral chromaffin cells (1974)
    Springer
    Cell & tissue research 148 (1974), S. 499-504 
    Details
    ISSN: 1432-0878
    Keywords: Urethra (rat) ; Chromaffin cells ; Sensory neurons ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The urethra of the rat was examined by transmission and scanning electron microscopy. Under a transmission electron microscope flask-shaped chromaffin cells containing membrane-bound osmiophilic granules were seen to possess microvilli at their apical surfaces. The microvilli projected into large extracellular spaces which were apparently in continuity with the lumen of the urethra. Using scanning electron microscopy, a surface view of the lumen of the urethra was obtained. It showed a gently undulating surface with distinct intercellular boundaries. Scattered over the surface were numerous deep depressions between individual cells. These were thought to correspond with the large extracellular spaces into which microvilli had been seen to project. It is suggested that urethral chromaffin cells may “trigger” the afferent part of a reflex causing contraction of the urethral longitudinal muscle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221934
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  • 88
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    Electronic Resource
    Ultrastructure of synaptosomes from one-day old and adult rat brain stem (1974)
    Springer
    Cell & tissue research 148 (1974), S. 535-550 
    Details
    ISSN: 1432-0878
    Keywords: Synaptosomes ; Rat brain stem ; Synaptogenesis ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure and protein content of the five subfractions of the crude mitochondrial fraction from the brain stem of the 1-day old and adult rat was examined. The morphological composition of the subfractions after fixation in glutaraldehyde and osmiumtetroxide in the adult rat brain stem resembled that previously reported for the whole brain; synaptosomes sedimented in a sucrose gradient in subfractions C and D. In the 1-day old rat, mature synaptosomes were found in subfractions A, B, C and D; E contained mainly free mitochondria. 80–95% of the processes in the adult and 10–30% in the 1-day old rat contained synaptic vesicles which were of four types: (1) small agranular vesicles (2) large dense core vesicles (3) large agranular vesicles (4) coated vesicles. Pre- and postsynaptic membrane thickenings were demonstrated in many nerve-ending particles. In the subfractions of the 1-day old rat the protein content was one half and the distribution resembled that in the adult. Evidently nerve endings develop faster in the brain stem than in cortical areas; a serotoninor adrenergic origin of the early synaptosomes is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221937
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  • 89
    Electronic Resource
    Electronic Resource
    Junctions in the central nervous system of the cat (1974)
    Springer
    Cell & tissue research 148 (1974), S. 577-586 
    Details
    ISSN: 1432-0878
    Keywords: Node of Ranvier ; Axonal-glial junctions ; Cat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The paranodal zone of myelinated nerve fibers from the CNS of cats has been studied by means of the lanthanum technique and after freeze-etching. Special interest was given to the axonal-glial zones of contact in this region. Examination of the membranes of the paranodal pockets and the axolemma revealed that the membrane thickenings which occur between the adjacent membranes actually consist of bands. The bands show a specific pattern of diagonal running subunits 10 nm apart. These substructures of the axonal side of the membrane contacts protrude outwards, i.e. towards the glial membrane, where they fit into depressions on the glial membrane surface. This arrangement in form of a “zip-fastener” makes the whole structure very flexible. The subdivision of the bands was identified with both techniques. The different membrane aspects obtained by the freeze-etching technique are discussed in respect to the splitting theory, and a hypothetical model of this membrane specialization is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221941
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  • 90
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    Electronic Resource
    The structural water of fibrin molecules measured by heat drying and compared with derivations from electron microscopic molecular models (1974)
    Springer
    Cell & tissue research 149 (1974), S. 379-398 
    Details
    ISSN: 1432-0878
    Keywords: Structural water ; Fibrinogen-Fibrinmolecule ; Molecular morphology ; Electron microscopy ; Heat drying
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Standardgerinnsel aus Rinderfibrin wurden in der Kammer einer Versuchsanordnung einem mit Wasser nahezu gesättigten Luftstrom ausgesetzt. Die Gerinnsel kollabierten, und ihr Restwasser wurde in Zeitabständen durch Hitzetrocknung bei 105°C bestimmt. Es resultierte eine zeitabhängige Kurve, die aus 3 Phasen besteht. Elektronen-mikroskopische Aufnahmen zeigen, daß infolge eines Verlustes des freien Wassers während der ersten Phase das Pibringerüst des Gerinnsels kollabiert. Während der dritten Phase kollabiert das Proteingerüst der Fibrinmoleküle infolge des Verlustes von Strukturwasser. Während der zweiten Phase besteht das Gerinnsel aus raumfüllend gepackten Fibrinmolekülen. Das Strukturwasser beträgt dann etwa 5,25 g/g Trockengewicht; die Höhe ist etwa 180 μm und ergibt den wahrscheinlichsten Wert des Strukturwassers, 6,25 g/g Protein. Wenn dieser experimentelle Wert mit entsprechenden, theoretisch zu erwartenden Werten verglichen wird, die von elektronenmikroskopischen Molekularmodellen für Fibrin hergeleitet wurden, so ergibt das Gerinnsel, das aus raumfüllend gepackten Pentagondodekaeder-Modellen besteht, mit etwa 8 g Strukturwasser/g Fibrin die beste Näherung an den im Experiment erhaltenen Wert. Dieses Modell kann — im Gegensatz zu anderen Modellen — Massen-, Volumens- und Morphologieverhältnisse des Gerinnsels und des Moleküls erklären. Die verbleibende Differenz zwischen wahrscheinlichstem experimentellem und theoretischem Strukturwasser-Gehalt ist leicht durch experimentelle Ungenauigkeiten und Anwesenheit von Nicht-Fibrin im Molekularvolumen erklärbar. Mit an Sicherheit grenzender Wahrscheinlichkeit repräsentiert deshalb das Pentagondodekaeder-Modell die Allgemeinstruktur des Fibrin- und Fibrinogenmoleküls.
    Notes: Summary Standard clots of bovine fibrin collapsed in the highly humid air stream of a laboratory device. Their residual water, determined by heat drying at 105°C, resulted in a time dependent curve composed of 3 distinct phases. Electron micrographs show that during the first phase free water is released causing a collapse of the fibrous framework of the clot, during the third phase structural water is lost causing a breakdown of the molecular protein. The clot of the second phase consists of space fillingly packed fibrin molecules, whose directly determined structural water is approximately 5.25 g/g dry wt., but whose height (approximately 180 μm) results in the most probable value 6.25 g structural water/g protein. If this amount is compared with respective theoretical values of electron microscopic molecular models of fibrin, the clot consisting of space fillingly packed pentagon dodecahedron models yields approximately 8 g structural water/g fibrin, closely to the experimental value. In contrast to other models, this model explains simultaneously the shape of the curve, mass and volume relationships and morphology of clot and molecule. The remainding difference between the most probable experimental and this theoretical value can easily be attributed to experimental errors and impurities contained in the volume of the molecule. Consequently, the general structure of the fibrinogen and fibrin molecule is represented by the pentagon dodecahedron model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226772
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  • 91
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    Electronic Resource
    Fluorescence and electron microscopical study of aminergic nuclei in the brain of Bufo poweri (1974)
    Springer
    Cell & tissue research 149 (1974), S. 481-495 
    Details
    ISSN: 1432-0878
    Keywords: Brain ; Monoamines ; Amphibia ; Fluorescence microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of monoamines in the brain of Bufo poweri was investigated with the Falck-Hillarp method. Green fluorescence was observed in neurons of the diencephalic preoptic recess organ (PRO) and its so-called additional cells, in the paraventricular organ (PVO) and its so-called accompanying cells, in the nucleus infundibularis dorsalis (NID) and in the mesencephalic nucleus reticularis mesencephali (NRM). Yellow fluorescence was found in some cells of the PVO and NID and in neurons of the caudal part of the NRM. Extensive tracts of aminergic fibres are described running caudo-rostrally and mainly terminating in the septa and striata of the telencephalon. It is suggested that the aminergic nuclei mentioned above partly contribute to the ascending tracts. Other fibres, originating in the PVO and NID are curving centro-caudally towards the median eminence. Although with the electron microscope some apparently aminergic nerve fibres were detected in the pars intermedia, such fibres have not been observed fluorescence microscopically. The ultrastructural study of the PRO has shown the presence of two types of aminergic liquor-contacting neurons. Among the distal cells of the PRO, aminergic and peptidergic neurons were distinguished. The presence of PRO additional cells, which are considered as a rostral extension of the PRO, is discussed with regard to the terrestrial habitat of the species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223027
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  • 92
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    Electronic Resource
    An electron microscopic and autoradiographic study of mesogleal organization and collagen synthesis in the sea anemone Aiptasia diaphana (1974)
    Springer
    Cell & tissue research 149 (1974), S. 537-554 
    Details
    ISSN: 1432-0878
    Keywords: Sea anemone mesoglea ; Collagen synthesis ; Epitheliomuscular cells ; Electron microscopy ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy and autoradiography (H3-proline) were used to determine the cell(s) responsible for collagen synthesis and lamination in the mesoglea of the sea anemone, Aiptasia diaphana. Mesogleal collagen is synthesized by the epidermal epitheliomuscular cells which contain much rough endoplasmic reticulum, and secretory vesicles attached to microtubules which cross the basal plasmalemma and anchor in the basement membrane; these cells incorporate large amounts of H3-proline. The mesogleal collagen fibers are non-striated, have clear centers, and a diameter of 200–260 Å; their walls are composed of 65 Å diameter subunit fibrils which appear to be helically oriented. Epitheliomuscular cells rest upon a subepidermal basement membrane which is composed of mesogleal collagen fibers, 65 Å subunit fibrils, and dense granules. This subepidermal basement membrane labels definitively with H3-proline, and is the region where soluble collagen precursors apparently form subunit fibrils which associate to yield mesogleal fibers. The columnar mesogleal collagen fibers are arranged to form layers: the fibers of each layer have the same longitudinal orientation, while those of adjacent layers display an approximate orthogonal arrangement. It is felt that the subepidermal basement membrane is responsible for this organization of mesogleal fibers. Mesogleal amoebocytes do not label with H3-proline and show no ultrastructural evidence of collagen secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223031
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  • 93
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    Electronic Resource
    Multinucleate spermatids in the mouse (1974)
    Springer
    Cell & tissue research 150 (1974), S. 323-329 
    Details
    ISSN: 1432-0878
    Keywords: Spermiogenesis ; Mouse ; Multinucleate spermatids ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscope studies of the testes of five inbred and three outbred mouse strains show that the usual frequency of multinucleate spermatids is between one and two percent. In C57 BL/6J and A/Gr however it is higher (4–5%). The frequency of the shared acrosome condition, which would lead to the formation of an abnormal sperm, is 1.3 per thousand.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220140
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  • 94
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    Electronic Resource
    Dissolution and removal of neuronal lipofuscin following dimethylaminoethyl p-chlorophenoxyacetate administration to guinea pigs (1974)
    Springer
    Cell & tissue research 150 (1974), S. 369-375 
    Details
    ISSN: 1432-0878
    Keywords: Lipofuscin ; Phagocytosis ; Vacuolization ; Capillary endothelium ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dimethylaminoethyl p-chlorophenoxy acetate (80 mg/kg body weight) was administered (i. m.) to guinea pigs for 30 to 56 days. Electron microscopic examination of the hippocampus, mid-brain reticular formation and the area postrema revealed marked diminution in the electron density of the pigment granules and vacuolization. This type of lipofuscin was detected in some phagocytic cells and in the capillary endothelium. Conspicuous vacuolization of the capillary wall was discernible. These changes were not observed in the “control group” of animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220143
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  • 95
    Electronic Resource
    Electronic Resource
    Acinar ultrastructure of the submandibular gland of Mus musculus during embryonic development (1974)
    Springer
    Cell & tissue research 150 (1974), S. 425-442 
    Details
    ISSN: 1432-0878
    Keywords: Glandula submandibularis (Mouse) ; Acinar ultrastructure ; Cell types ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the submandibular gland of the mouse was studied by means of electron microscopy, from the 14th day of gestation up to birth. In the first two days the acini are solid and their cells contain polyribosomes and a few lamellae of endoplasmic reticulum. Beginning with the 16th day secretory granules appear and rapidly fill an increasing number of cells. The different electron density of the granules makes it possible to distinguish 1. two types of granules, dense and pale, and sometimes intermediate ones, 2. “polymorphic” granules. The latter consists of electron dense and electron pale parts combined in different configurations. The possible significance of the various types of granules is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225967
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  • 96
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    Electronic Resource
    Electron microscopic investigation of synaptic organization of the trochlear nucleus in cat (1974)
    Springer
    Cell & tissue research 150 (1974), S. 409-423 
    Details
    ISSN: 1432-0878
    Keywords: Synaptic organization ; Trochlear nucleus ; Cat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two distinct types of neuron in the cat trochlear nucleus (one large, one small) are described, the α- and γ-motoneurons, respectively. Four types of terminals are observed which establish axo-dendritic synapses. Two of them (Types I and II) perform axo-somatic synapses as well. Terminals en passant (Types I and II) are predominant. The Type I terminal is long and slender with a characteristic distribution of the axoplasmic organelles and the unique feature of a relative narrowing of the synaptic cleft as compared to the width of the neighboring extracellular space. Its vesicle population is pleomorphic and a conspicuous glial barrier surrounds the synaptic zones. The Type II terminal differs slightly from Type I, revealing a wider synaptic cleft and lacking a characteristic distribution of the axoplasmic organelles. The type III terminal is rarely observed performing axo-somatic synapses, but is a common finding in the neuropil. Post-junctional dense bodies are often present in its axodendritic synapses. The Type IV nerve terminal performs axo-dendritic synapses and is characterized by a rich content of large granulated vesicles. Axo-axonal synapses are observed only very rarely. The synaptic organization of the feline trochlear nucleus is compared with the synaptic morphology of the oculomotor nuclei of inframammalian species (Waxman and Pappas, 1971). In addition to certain similarities (e.g., richness of synapses en passant), significant differences are encountered: the present study provides no morphological evidence for electrotonic transmission in the trochlear nucleus of cat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220147
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  • 97
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    Electronic Resource
    Quantitative studies on the distribution of myofilaments in intrafusal muscle fibres (1974)
    Springer
    Cell & tissue research 150 (1974), S. 521-527 
    Details
    ISSN: 1432-0878
    Keywords: Muscle spindle ; Intrafusal fibres ; Myofilaments ; Electron microscopy ; Quantitative stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Muscle spindles contain two types of intrafusal muscle fibre, nuclear bag fibres and nuclear chain fibres. The intrafusal fibres of rabbit and guinea pig spindles have been studied using quantitative stereological techniques at the ultrastructural level. The crosssectional areas occupied by myofilaments have been measured in the polar and equatorial regions of both types of intrafusal fibre. There are considerably fewer myofilaments in the equatorial regions of both types of fibre compared with their polar regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225975
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  • 98
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    Electronic Resource
    Investigations on turnover of adrenocortical mitochondria (1974)
    Springer
    Cell & tissue research 151 (1974), S. 281-292 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Mitochondria ; ACTH ; DNA-synthesis ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a chronic ACTH administration (up to 12 consecutive days) on the 3H-thymidine uptake by the mitochondrial compartment of rat adrenal zona fasciculata were investigated by high resolution autoradiography, and compared with the changes in volume and number per cell of these organelles induced by the hormonal treatment. Up to the 9th day of treatment there is a significant increase in the tracer incorporation into adrenocortical mitochondria which is coupled with a significant increase in the volume of the organelles. After 12 days of hormone administration a significant decrease in the 3H-thymidine mitochondrial uptake is found, which is associated with a conspicuous increase in the number of mitochondria per cell and a net decrease in their average volume. The data are discussed in the light of evidence indicating that mitochondria possess a genetic apparatus largely independent of nuclear control. It is hypothesized that ACTH controls the growth and proliferation of adrenocortical mitochondria and that the mechanism of this action of ACTH involves stimulation of the mitochondrial DNA synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224539
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  • 99
    Electronic Resource
    Electronic Resource
    Fine structural localization of nucleoside triphosphatase and acid phosphatase activity in Trichomonas vaginalis donné (1974)
    Springer
    Cell & tissue research 151 (1974), S. 269-280 
    Details
    ISSN: 1432-0878
    Keywords: Trichomonas vaginalis ; Adenosine triphosphatase ; Acid phosphatase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two intracellular phospho-hydrolases are revealed in cells of Trichomonas vaginalis. One of the enzymes is an acid phosphatase and the other a nucleoside triphosphatase (ATP-ase). Both enzymes are found to be present in the Golgi saceuli and vesicles of the cells. The ATP-ase activity has prevalence to the more superficially positioned saceuli of the Golgi region and the acid phosphatase to the more deeply positioned saceuli. Both enzymes are also found in the phagolysosomes but only acid phosphatase could be demonstrated in the small primary lysosomal structures of the cell cytoplasm. The findings indicate that both enzymes are active in the hydrolytic processes associated with endocytosis of foreign matter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224538
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  • 100
    Electronic Resource
    Electronic Resource
    Freeze-fracture studies on the cockroach hemocyte membrane complex: Symmetric and asymmetric membrane particle distributions (1974)
    Springer
    Cell & tissue research 151 (1974), S. 385-394 
    Details
    ISSN: 1432-0878
    Keywords: Membrane particles ; Cockroach hemocytes ; Freeze-fracture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Freeze-fracture studies were conducted on the membranes of normal cockroach hemocytes. The plasmalemma is asymmetric with the A fracture face containing 80–100 Å membrane intercalated particles at a concentration of ∼2500/μ2. The B fracture face contains 120–150 Å particles with a relatively low density (∼800/μ2). The nuclear envelope displays an asymmetry with the A fracture face containing ∼1500 particles/μ2 and the B face containing ∼300/μ 2. No significant particle size differences were observed in nuclear envelope fracture faces. Two types of symmetric membranes were also found in these cells. Both A and B fracture faces of the membrane surrounding the numerous cytoplasmic inclusion bodies contain particle sizes and concentrations similar to the B face of the plasmalemma. A second type of symmetry was observed in cells apparently engaged in “exocytosis”. Vesicles (∼0.1 μD) from this process were completely particle free on both fracture faces. Such particle free vesicles could be found in the cytoplasm, attached to the plasmalemma, or completely separated from the cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224548
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