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  • Electron microscopy  (1,025)
  • 1975-1979  (599)
  • 1970-1974  (426)
  • 1
    ISSN: 1432-072X
    Keywords: Alcohol dehydrogenase ; Acetaldehyde dehydrogenase ; Clostridium kluyveri ; Electron microscopy ; Polygonal bodies ; Enzyme complex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The alcohol-acetaldehyde dehydrogenase complex of Clostridium kluyveri has been separated from contaminating β-hydroxybutyryl-CoA dehydrogenase by repeated precipitation with manganese and ammonium sulfate. Mn++ was required for maximum alcohol dehydrogenase activity. The molecular weight of the enzyme complex was 194,000 as determined by sucrose density gradient centrifugation. The enzyme complex has been shown to contain two types of subunits with molecular weights of 55,000±2,600 and 42,000±1,200, respectively which are arranged in “H”-shaped particles. In solutions with an ionic strength above 25 mM the enzyme complex precipitated in the form of lumps as has been shown with specific ferritin-conjugated antibodies. These lumps are assumed to be aggregated polygonal bodies present in C. kluyveri.
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  • 2
    ISSN: 1432-072X
    Keywords: Bacillus subtilis ; Cell cycle ; DNA replication ; Cell division ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bacillus subtilis strain Marburg was grown exponentially with a doubling time of 65 min. To follow the time course of various cell cycle events, cells were collected by agar filtration and were then classified according to length. The DNA replication cycle was determined by a quantitative analysis of radioautograms of tritiated thymidine pulse labeled cells. The DNA replication period was found to be 45 min. This period is preceded and followed by periods without DNA synthesis of about 10 min. The morphology and segregation of nucleoplasmic bodies was studied in thin sections. B. subtilis contains two sets of genomes. DNA replication and DNA segregation seem to go hand in hand and DNA segregation is completed shortly after termination of DNA replication. Cell division and cell separation were investigated in whole mount preparations (agar filtration) and in thin sections. Cell division starts about 20 min after cell birth; cell separation starts at about 45 min and before completion of the septum.
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  • 3
    ISSN: 1432-1106
    Keywords: Intrahypothalamic connections ; Deafferentation ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Terminal degeneration within the hypothalamus was studied by electron microscopy 1 or 2 days (1) after carefully placed microlesions in the arcuate, anterior periventricular, ventromedial, premammillary and posterior hypothalamic nuclei and (2) after microlesions placed in the hypothalamus deafferented 3 weeks earlier. In the median eminence terminal degeneration was found after each of these lesions. Projections from the ventromedial nucleus reach the arcuate, suprachiasmatic, and anterior periventricular nuclei. Projections from the arcuate nucleus terminate in the medial preoptic, anterior periventricular, and ventromedial nuclei. After lesioning the premammillary nuclei degeneration was found in the supraoptic, arcuate, anterior hypothalamic and ventromedial nuclei.
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  • 4
    ISSN: 1432-1106
    Keywords: Hypothalamic paraventricular nucleus ; Spinal projection neuron ; Hypophyseal projection neuron ; Horseradish peroxidase ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The distribution of labeled neurons in the paraventricular nucleus of the hypothalamus (PVN) was studied following injections of horseradish peroxidase (HRP) into the spinal cord (C8 to T1) or the hypophysis in the rat. Injections were also made in the spinal cord in another group of animals, which were subjected to water deprivation for a period of 3 days, and the PVN of these animals was examined with the electron microscope. Spinal projection neurons (paraventriculospinal tract, PVST, neurons) formed two groups; the dorsal and the ventral groups. They were located within the parvocellular part of the PVN and fused into one at the caudal level. The neurons of the dorsal group were well assembled whereas those of the ventral group were intermingled with paraventriculohypophyseal tract (PVHT) neurons, which were concentrated in the magnocellular part. Electron microscopic observations revealed that HRP-labeled neurons after spinal injections did not contain neurosecretory granules and that they were not affected by water deprivation. On the other hand, neurons containing a number of neurosecretory granules displayed a significant degree of dilatation of the endoplasmic reticulum as the result of water deprivation. These neurons contained no HRP granules. The present findings suggest that the PVST neurons are distinct from the PVHT neurons and that the neuronal groups of both systems form different cell columns within the nucleus.
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  • 5
    ISSN: 1432-2307
    Keywords: Emiocytosis ; Endocrine cells ; Human embryo, child and adult ; Large intestine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In endocrine cells of the colon of adults, children and fetuses, exocytotic granule release without any specific stimulation is reported. Omega-invaginations are observed on both the lateral and basal surfaces of all types of colonic endocrine cells. Several explanations for the phenomenon are suggested: 1) emiocytosis is probably more frequent in the colon than in the proximal gut, this allows its observation without requiring an exogenous stimulus, 2) since most of the exocytotic figures are from anaesthetized subjects it is also assumed that contraction of the muscular layer induced by anaesthetics and the resulting increase in intraluminal pressure were the possible causes of granule release, 3) in non-anaesthetized subjects release may have taken place in response to a normal endogenous physiological stimulus, or to the dilation of colon during colonoscopy. Less likely is an effect associated with the preparation for colonoscopy. Certain figures on lateral surfaces between endocrine and adjacent cells i.e., bulges of parallel plasma membranes surrounding a secretory granule, were observed. Their significance is unknown.
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  • 6
    ISSN: 1432-2307
    Keywords: Cerebro-hepato-renal syndrome ; Zellweger's syndrome ; Peroxisome deficiency ; Liver cirrhosis ; Liver biopsy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary For histologic differential diagnosis of fibrotic and cirrhotic liver changes in early infancy Zellweger's cerebro-hepato-renal syndrome has to be considered. A case is reported where a female newborn failed to thrive and developed severe muscular hypotonia, defective intelligence, and seizures. At an age of 12 months an open biopsy was taken from the enlarged liver. Biochemical tests for disorders of carbohydrate metabolism were negative. The light microscopic examination showed severe fibrosis, lobular disarray, and single cell necroses. Neither siderin nor bile pigment could be detected. There were no changes of the small bile ducts and no signs of inflammation — the child died at 18 months. A postmortem needle biopsy of the liver showed the advanced stage of micronodular cirrhosis. The electron microscopic examination of the first biopsy revealed hypertrophy of smooth endoplasmic reticulum, probably induced by anticonvulsive drugs. The mitochondria showed an increase in the density of their matrix and in the number of sometimes tubular cristae. In accordance with reports in literature, no regular peroxisomes (microbodies) could be found in the hepatocytes. Only a very few profiles with an average diameter of 0.16 μm looked like rather small peroxisomes. The cytoplasmic volume fraction of those organelles, however, amounted to 3×10−5 which is only 1/500 of the normal value in human hepatocytes. Although the significance of the absence of peroxisomes is not yet definitively proved, the term ‘Peroxisome Deficiency’ is proposed as a name which probably is more closely related to the pathogenetic mechanism than the hitherto usual designation cerebro-hepato-renal syndrome.
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  • 7
    ISSN: 1432-2307
    Keywords: Glomerulonephritis ; Cryoglobulinemia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Renal tissue from five patients with cryoglobulinemia was studied by light and electron microscopy and immunofluorescence. None of the histologic features observed at the light microscopic level seems to be specific for cryoglobulinemia. Electron microscopic investigations have shown very large electron dense deposits in almost every examined lobule in all cases. The deposits displayed two main patterns; a homogeneous texture in two cases and tubular or annular structures in three cases. The patients with typically structured deposits had IgG-IgM cryoglobulinemia (2 cases) or monoclonal IgM cryoglobulinemia (1 case). The presence of IgM in cryoglobulinemia may be the cause of the peculiar structure of the deposits.
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  • 8
    ISSN: 1432-2307
    Keywords: Cloacogenic carcinomas ; Ano-rectal region ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The clinical and pathological features of four transitional cloacogenic carcinomas (TCC) are presented with particular reference to electron microscopy. The incidence of this tumour is 1.4% of all ano-rectal neoplasms. Three cases showed a gross appearance similar to the common rectal neoplasms. One tumour presented without an intraluminal lesion, but infiltrated the bowel wall and the anal glands. TCC show a distinct histological pattern. The degree of differentiation of the basic transitional cell component determines the “grading” of the lesion. We distinguish between grade I, II and III. Grade I lesions show uniform polygonal cells with only occasional mitotic figures. There is distinct palisading of the nuclei of the peripheral tumour cell layers. Grade II lesions are characterized by partial or total loss of the peripheral palisading. Grade III lesions are extremely anaplastic (“oat cell” carcinoma). This histological classification correlates well with the prognosis. Electron microscopic investigation of TCC revealed the ultrastructural features of basal cells. The uniform tumour cells with large nuclei contain tonofibrils, desmosomes and hemi-desmosomes, free ribosomes, and relatively few other organelles. We did not find keratinocytes or keratohyalin granules in these four cases of TCC. It is emphasized that TCC of the ano-rectal region differ fundamentally from the basalcell carcinomas of the skin in their biological behaviour.
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  • 9
    ISSN: 1432-2307
    Keywords: Amyloidosis ; cyclic hematopoiesis ; Animal model ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy studies were made on tissues of cyclic hematopoietic (CH) dogs of various ages presenting a high incidence of spontaneous amyloidosis. The distribution and morphologic characteristics of amyloidosis in this animal model closely correspond to the secondary and familial forms of the disease in humans. Plasma cells and, particularly, macrophages presented marked changes during the evolution of amyloid deposition. Residual bodies in the macrophages contained abundant cell debris, a result of both endocytic and autophagocytic activities. Intracellular amyloid fibrils were not observed by conventional electron microscopy. A few reticular cells contained intracytoplasmic fibrils which were morphologically different from amyloid. There was no correlation between the amount of intracellular fibrils and the size of the extracellular amyloid deposits. On the contrary, a temporal association between the magnitude of the amyloid deposits and cytoplasmic changes in the macrophages at sequential stages of the evolution of the disease was evident. It is suggested that the hematopoietic defect in the CH dog could play an important role in the production of amyloidosis, making this animal an excellent experimental model for studies of that disease.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 385 (1979), S. 117-124 
    ISSN: 1432-2307
    Keywords: Liposarcoma ; Breast ; Histopathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of primary liposarcoma of the breast in a 65-years-old woman is described by light- and electron microscopy. The patient had previously had a cystosarcoma phyllodes removed from the same area. A review of the literature showed 34 previously published cases of liposarcoma of the breast, which regarding age distribution, histological type and pattern of metastasis corresponded to liposarcomas of the lower limbs.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 46 (1979), S. 235-237 
    ISSN: 1432-0533
    Keywords: Paraganglioma ; Cauda equina region ; Neurosecretory granules ; Nerve fibers ; Endothelial cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Some new ultrastructural observations are documented in a paraganglioma in the cauda equina region. These include the presence of nerve fibers in the tumor capsule, clear vesicles and tubulo-vesicular structures in some cytoplasmic processes in the tumor, fenestrated endothelial cells, and numerous tubular bodies in some endothelial cells.
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  • 12
    ISSN: 1432-0533
    Keywords: Acromegaly ; Electron microscopy ; Growth hormone ; Pituitary adenoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Unusually large, oval and pleomorphic secretory granules were noted by electron microscopy in an acidophilic adenoma of the pituitary. The tumor, which was removed by surgery from a 42-year-old woman with elevated blood growth hormone levels and the clinical features of acromegaly, was found to contain growth hormone by the immunoperoxidase technique. This ultrastructural abnormality of secretory granules was not reported so far and was not seen among the 58 cases of growth hormone-producing adenomas investigated in our laboratory. The present case clearly shows that the cytogenesis and cellular composition of pituitary adenomas cannot be determined by solely examining the size and shape of secretory granules.
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  • 13
    ISSN: 1432-0533
    Keywords: Dysplastic gangliocytoma ; Cerebellum ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of a dysplastic gangliocytoma of the cerebellum is studied by means of the Golgi method and electron microscopic examination. Thick proximally unbranched dendrites with terminal arborizations and varicose influorescences in the form of a basket are stained with the Golgi method. Axons are always descendant to the inner myelinated layer of the redistributed cerebellar cortex, while ascendant collaterals are observed at the level of the outer myelinated layer. Clear and dense-core vesicles and synapses are common in the cellular profiles under electron microscopic examination. From these data and because of the lack of putative connections through the white matter, an organized, self-regulated, catecholamine-mediated complex may be postulated.
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  • 14
    ISSN: 1432-0533
    Keywords: Experimental tumors ; Tissue culture ; Scanning ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Serially transplanted neurogenic tumors of experimental origin were explanted in vitro and analyzed by scanning electron microscopy. In explants of intracerebrally transplanted gliomas, small stellate cells with branching processes were observed; in transplanted tumors of the peripheral nervous system, slender bipolar cells as well as fibroblasts emerged. The stereoscopic features were compared with the picture of conventional light microscopy. The findings are consistent with the assumption of the glial derivation of CNS-tumors induced with neurotropic alkylating carcinogens. The peripheral tumors are composed of Schwann-cell like elements and fibroblasts. The significance of the results for the cytogenetic derivation of brain tumors are discussed.
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  • 15
    ISSN: 1432-0533
    Keywords: Cerebral blood vessels ; “Overgrowth” ; Embryonic development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cerebral capillaries in “overgrown” neural tissue of chick embryo brains ranging in age from 5–18 days of incubation were studied by means of electron microscopy. The vessels in the abnormal tissue showed more extensive and prolonged interdigitations and overlapping of adjacent endothelial cells than did those in normal control brains. In the abnormal neural tissue the appearance and distribution of endothelial cell organelles was similar to that in normal tissue; however, the Golgi complex was less highly developed, and there was an increased amount of coated vesicles in the capillaries of the abnormal brains.
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  • 16
    ISSN: 1432-0533
    Keywords: Sensory neuropathy ; Nerve biopsy ; Electron microscopy ; Quantitative study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscope study and quantitation of myelinated and unmyelinated fibers of seven nerve biopsies performed in sporadic cases of idiopathic sensory neuropathy is reported. The number of myelinated fibers is markedly decreased or absent in every case. On the contrary, the unmyelinated fiber numbers are normal or increased. In most cases, the small diameter myelinated and unmyelinated fibers proportions are higher than those of control biopsies. The electron microscope study discloses evidence of degeneration of Wallerian type and regeneration is also indicated by quantitative studies. Regenerative phenomena seem more obvious in sporadic cases than in previously reported studies of familial cases.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 48 (1979), S. 63-66 
    ISSN: 1432-0533
    Keywords: Acute multiple sclerosis ; Virus-like particles ; Demyetination ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Novel, superficially ‘virus-like’ hollow-cored particles 50–60 nm in diameter were found in the perivascular extracellular space of the brain from a patient who died with acute multiple sclerosis (MS). It is concluded that they are not virions but are derived from myelin undergoing vesicular demyelination. This case demonstrates the need for caution in the interpretation of unusual electron microscopic appearances.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 48 (1979), S. 95-103 
    ISSN: 1432-0533
    Keywords: Schmidt-Lanterman incisures ; Electron microscopy ; Nerve crush ; Wallerian degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The electron microscopy of changes at Schmidt-Lanterman incisures in Wallerian degeneration has been described only briefly previously. We have demonstrated that the changes up to 36 h after nerve crush are chiefly peri-incisural. At 12h and 24h ‘incisural dilatation’ consisted of an intraperiod line separation of peri-incisural myelin lamellae, which began among inner (adaxonal) lamellae extending later to outer (abaxonal) lamellae. The incisure itself showed little or no change. At 36 h, ovoid formation was apparent in most fibres. The sites of fibre cleavage to form ovoids occurred adjacent to incisures at the focal regions of myelin lamellae separation. Even within ovoids the incisures themselves remained intact at 36 h. The fine structural changes at incisures following nerve crush provide an understanding of the increased perceptibility of incisures by light microscopy during early Wallerian degeneration.
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  • 19
    ISSN: 1432-0533
    Keywords: Complete cerebral ischemia ; Postischemic recirculation ; Electron microscopy ; Nuclear perturbations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal, astrocytic, and oligodendrocytic elements in several brain loci of the cat were examined at the light and electron microscopic level immediately after periods of complete cerebral ischemia (CCI) uncomplicated by post-ischemic recirculation. Such CCI episodes ranged from 1.5–25 min duration and were methodically produced in a cat model employing rigorous physiological controls. Subsequent to these CCI insults, morphological alterations occurred in a homogeneous manner within each cell type of all loci examined; however, variation in the temporal onset and magnitude of alterations among the various cell types was observed. With brief ischemic insults all cell nuclei demonstrated pronounced nuclear alterations, while their cytoplasmic organelles displayed minimal change. Chromatin clumping and nucleolar condensation were observed in both neurons and glia subsequent to 1.5–5 min of CCI, respectively. With increasing durations of CCI such changes were more dramatic and conspicuous alterations of the cytoplasmic organelles were observed. On the basis of extensive morphological analyses the present study illustrates that nuclear alterations are the first to occur subsequent to CCI. The homogeneity of neuronal involvement seen subsequent to CCI uncomplicated by post-ischemic recirculation is inconsistent with the “selective vulnerability” purported to occur by others. The significance of this inconsistency remains to be assessed; yet, the suggestion is advanced that post-ischemic recirculation may be a factor in the genesis of such vulnerability.
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  • 20
    ISSN: 1432-0533
    Keywords: Mucopolysaccharidosis II ; Prenatal diagnosis ; Electron microscopy ; Lysosomal storage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light and electron microscopic findings in the nervous system of a 23-week-old fetus are reported, in which MPS II was diagnosed prenatally. The degrees of myelination and neuronal differentiation were similar as in a normal fetus of the same age. A storage of mucopolysaccharides in typical vacuolar inclusion bodies was present throughout the peripheral and central nervous system, mainly in cells of mesenchymal origin. “Zebra” bodies and granulo-membranous bodies, which are thought to represent secondary ganglioside accumulation were only found in the well developed neurons of the spinal cord and spinal ganglia, but not in the poorly developed neurons of the cerebellar and cerebral cortex. Mucopolysaccharide storage in endothelial cells of cerebral blood vessels precedes the appearance of lipid storage in cerebral neurons.
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  • 21
    ISSN: 1432-0568
    Keywords: Limb bud ; Periderm ; Apical ectodermal ridge ; Electron microscopy ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Development of periderm cells covering fore-and hindlimb buds of mouse em`ryos was observed by scanning and transmission electron microscopy at half day intervals from day 9.5 to 12.5 of gestation (vaginal plug=day 0). At day 9.5, the epidermis is single layered. Occasional periderm cells are present at day 10.5. By day 11.5 a complete layer of periderm cells has covered the entire limb bud. By scanning electron microscopic observation, periderm cells covering the apical ectodermal ridge (AER) are characterized by a small surface size and an elongated polygonal shape with the long axis parallel to the antero-posterior contour of the apical rim. Periderm cells covering the dorsal and ventral surfaces of the limb bud are relatively large and have a polygonal surface shape. The periderm covering the apical tip reflects well the developmental state of the AER. Hence, it is possible to estimate the development of the AER by observing the surface features of the apical periderm by scanning electron microscopy.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 158 (1979), S. 41-50 
    ISSN: 1432-0568
    Keywords: Placenta (human) ; Syncytiotrophoblast ; Intercellular junctions ; Electron microscopy ; Freeze-fracturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Inter-and intrasyncytiotrophoblastic junctions within the human full term placenta were electronmicroscopically investigated using thin sections and freeze-fracturing. Narrow clefts were occasionally situated between surface areas where adjacent chorionic villi exhibited close contact. Whithin these clefts, extensive zonulae and maculae occludentes and numerous maculae adherentes were found. The zonulae occludentes showed a continuous and irregular course on the membrane surface, and the maculae occludentes were irregularly distributed over extended membrane areas. Besides these areas, maculae occludentes and maculae adherentes were observed on infoldings and invaginations of the syncytiotrophoblastic surface membrane. Investigations of the inner surface of the syncytiotrophoblastic layer, that is, the layer facing the villous stroma, also revealed invaginations joined by maculae adherentes. The functional significance of the inter-and intrasyncytiotrophoblastic junctions is discussed with respect to the differentiation of the trophoblast.
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  • 23
    ISSN: 1432-0568
    Keywords: Cerebellar cortex ; Pre-and postterminal blood vessels ; Rhesus monkey, cat, rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the rhesus monkey, cat and rat, pial arteries give off branches which run vertically through all three layers of the cerebellar cortex. The large cortical arteries are surrounded by a perivascular space in the molecular layer. Their wall consists of several layers of smooth-muscle cells and the luminal endothelium. As the arteries reach the deeper layers of the cerebellar cortex, the number of smooth-muscle cells is reduced. In the rat, sometimes no smooth-muscle cells are detectable in the preterminal arterial vessels. If these deep arteries branch off by dichotomy of terminal vessels there occurs a gradual or complete loss of myocytes in all three species. In the cat, where cortical arteries give off branches at rightangles, there is a sphincter-like accumulation of smooth-muscle cells at the opening to the smaller branch. The postterminal vessels and veins in all species exhibit the smae mural structure found in capillaries. The wall consists only of an endothelium and occasional pericytes embedded in the basal lamina. Even the large veins which run to the pial veins show this simple mural structure.
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  • 24
    ISSN: 1432-0568
    Keywords: Parotid gland ; Miniature pig ; Electron microscopy ; Innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This communication reports on the morphology of the parotid gland of miniature pigs (Göttingen strain). 1. The glandular system consists in its terminal portions of acinar secretory parts. Between the basal lamina and the secretory epithelial cells myoepithelial cells are located. 2. The cytoplasmic organization of the acinar cells represents the features of mucous secretory cells. By electron microscopic means, light secretory granules have been demonstrated which frequently are coalescent. Between the bulk of secretory material only small remnants of cytoplasm are visible. The electron dense nuclei are located in basal parts of the cells. Intercellular canaliculi have not been observed. 3. The intercalary ducts, located between the acinar portions and the striated ducts of the gland, are long and narrow tubules, frequently branched. Their epithelium is simple cuboidal, and there is no indication of any secretory activity. 4. The epithelium of the striated ducts is simple columnar. The orientation of mitochondria parallel to the cell axis, and also the invaginations of the basal cell membrane give the basal cytoplasm a vertically striated appearance. 5. The paravascular nerves of the gland's connective tissue consist of bundles of unmyelinated axons. These branch into smaller bundles, and finally into single unmyelinated axons which reach the acinar portions. These axons appear to be only partly surrounded by Schwann cells. Very thin axons alone penetrate the basal lamina and reach the secretory cells of the acini; moreover, these axons may occasionally reach the intercellular spaces between the secretory cells. Within these terminal parts of the axons groups of synaptic vesicles appear.
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  • 25
    ISSN: 1432-0568
    Keywords: Electron microscopy ; Metrial gland (rat) ; Pregnant uterus ; Degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural changes occurring in the metrial gland in the latter half of pregnancy in the rat have been studied. Typical palely stained granulated cells are present in the metrial gland up to day 20 but many granulated cells show variations in appearance which may be associated with degeneration. In some the cytoplasm is more darkly stained and such cells often have apparently empty areas of cytoplasm adjacent to the granules. From day 14 onwards many areas of the gland show cellular debris, apparently resulting from lysis of the granulated cells. However, occasionally normal granulated cells are present in blood vessels and have been observed apparently penetrating the vascular endothelium. A variety of changes was also noted in the stromal cell population. Inclusions became apparent in many of these cells; some of these consisted of lipid while others resembled granules from the typical granulated cells. Other cells with numerous inclusions appeared to be macrophages. Lysis of granulated cells in situ is compatible with suggestions that the metrial gland produces a holocrine secretion, though some normal granulated cells enter blood vessels. The stromal cells may have a phagocytic role in late pregnancy but evidence for this was inconclusive.
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  • 26
    ISSN: 1432-0533
    Keywords: Paramyxovirus infection ; Ependyma ; Choroid plexus ; Electron microscopy ; Immunofluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of intracerebral inoculation of Sendai virus into young adult mice were investigated by immunofluorescence, light, and electron microscopy. Immunofluorescence of virus-specific antigens was maximal on the third day after inoculation, revealing infection of leptomeninges, ependyma, and choroid plexus. Histologically, meningitis, ependymitis, and choroiditis occurred between the second and third days. The choroiditis was associated with formation of vacuoles within the cytoplasm of epithelial cells. The vacuoles reached diameters up to 50 μm. The ubiquitous vacuolization of plexus epithelia resulted in a honeycomb-like pattern. Opaque viral inclusions were visible within the cytoplasm of choroidal and ependymal epithelium as well as in mononuclear inflammatory cells. On electron microscopy, they were composed of intracytoplasmic nucleocapsid accumulations. Viria lay free between microvilli of plexus epithelial cells, and budding virus structures were observed at cellular surfaces. Occasionally, complete viria occurred in the cytoplasm of plexus epithelial cells and were surrounded by a unit membrane from which they appeared to arise by budding. The formation of this small cavity can be interpreted as the first stage of vacuole formation.
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  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 46 (1979), S. 139-144 
    ISSN: 1432-0533
    Keywords: Perineurium ; Peripheral ganglion ; Diffusion barrier ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The perineurial diffusion barrier to horseradish peroxidase (HRP) and ferritin was investigated in superior cervical ganglia of rats and mice. The ganglion was surrounded by a delicate epineurium and 2–5 perineurial lamellae joined by zonulae occludentes and desmosomes. Following local application of tracers the animals were killed after 5, 30, and 60 min and the distribution of HRP and ferritin was studied by light and electron microscopy. The inner layers of the ganglionic perineurium prevented diffusion of both HRP and ferritin into the endoneurium. Owing to the fewness of the perineurial lamellae investing the ganglion. HRP had often extended to the innermost lamella 60 min after application. HRP and ferritin were present in vesicles of ganglionic perineurial cells. There was no passage of tracers via intercellular junctions.
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  • 28
    ISSN: 1432-0533
    Keywords: Alexander's disease ; Rosenthal's fibers ; Peripheral Nerve ; Electron microscopy ; Neurochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report the results of a cerebral and of a neuromuscular biopsies and of the autopsy findings in another infantile case of Alexander's disease in a girl. They review the 17 previously reported cases of this disease and the various etiopathogenic hypotheses mentioned. The presence of numerous, sometimes abnormal enlarged mitochondria and of abundant membranous cytoplasmic bodies in the astrocytic cytoplasm seems to be unreported elsewhere. Peripheral nerve changes are mentioned for the first time.
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  • 29
    ISSN: 1432-0533
    Keywords: Experimental Concussion ; Peroxidase, neuronal uptake ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal inundation with i.v. infused horseradish peroxidase was studied following concussive brain injury by means of both light and electron microscopy. In animals sustaining mechanical brain injury of insufficient intensity as to elicit either microscopic intraparenchymal hemorrhage or other neuropathological change, yet of sufficient intensity as to provoke a physiological concussive response, vascular peroxidase exudation concomitant with neuronal peroxidase inundation occurred throughout the raphe and reticular core. Initially such inundated neurons were totally flooded with the tracer and as such appeared reminiscent of cells visualized in Golgi preparations. However, over the course of a 24-h period these peroxidase flooded neurons apparently organized the peroxidase into vesicles and vacuoles which assumed a perinuclear position from where the peroxidase ultimately reached both the nucleus und nucleolus. It was remarkable that these events occurred without any evidence of subcellular alteration. We interpret such initial inundation with this protein tracer, its ultimate reorganization, and its nuclear and nucleolar uptake as being consistent with some form of subtle and transient neuronal perturbation. We speculate that as such this neuronal perturbation may constitute a morphological correlate of the concussive episode.
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  • 30
    ISSN: 1432-0533
    Keywords: Virus-like particle ; Nucleic acid ; Muscle ; Cytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Picornavirus-like crystalline arrays were found in the skeletal muscle of a victim of a traffic accident. Individual particles measured approximately 22 nm in diameter and were arrayed in a hexagonal or triangular pattern. Cis-platinum (II) staining of these virus-like particles showed that these particles were not glycogen but contained nucleic acids, and the staining according to Bernhard also showed these particles contained RNA. Through the combination of the methods of Heinen (1977) and Bernahrd (1969), we can confirm that virus-like crystalline structures found electron microscopically contain nucleic acids and possibly represent virions.
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  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 46 (1979), S. 169-172 
    ISSN: 1432-0533
    Keywords: Giant axonal neuropathy ; CNS ; Dog ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pathology of the central nervous system (CNS) in a dog with giant axonal neuropathy (GAN) is presented. Swollen axons containing excessive and disorganised neurofilaments were present in the spinal cord, mainly at the distal portions of long tracts. The fasciculus gracilis and dorsal spinocerebellar tracts were affected only in the rostral cervical cord while the lateral cortico spinal tract was principally involved in the lower thoracic and lumbar cord. Occasional swellings were also found in the central dorsal columns of the rostral lumbar segments and in the dorsal and intermediate grey matter. The nuclei gracilis and cuneatus, restiform body and ventral spinocerebellar tracts were all involved in the brain stem. Spheroids were seen in the white matter of the rostral cerebellar vermis and in the granule cell layer. The brachium of the superior colliculus contained swollen axons and the cortex was diffusely involved with spheroids. The distribution was of a distal axonopathy and the cortical changes provided an explanation for the abnormal EEG and mental retardation found in some human patients.
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  • 32
    ISSN: 1432-0533
    Keywords: Herpes simplex virus ; Organotypic nerve cell cultures ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In HSV-2 infected cultures, intranuclear tubule-like structures were found more commonly in fibroblasts and central nervous system (CNS) neurons than in oligodendrocytes, astrocytes, satellite and Schwann cells, but were found least often in peripheral neurons.
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  • 33
    ISSN: 1432-069X
    Keywords: Hyalinosis ; Electron microscopy ; Glycosaminoglycan ; Glycoprotein ; Cross-banded structure ; Schlüsselwörter ; Hyalinose ; Elektronenmikroskopie ; Glykosaminoglykan ; Glykoprotein ; Struktur mit Querstreifen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Systematisierte Hyalinose (Juvenile Hyaline Fibromatose) ist durch die hyalinisierten Hautefflorescenzen gekennzeichnet. Die elektronenmikroskopische Untersuchung eines hyalinisierten Hauttumors von einem 19jährigen Mann mit diesem Syndrom ergab, daß die Hyalinsubstanz sich aus den Rutheniumrot-positiven Ultrastrukturen des Glykosaminoglykans oder des Glykoproteins (d. h. Körnchen, Fäden und einer Struktur mit Querstreifen) und einigen dünnen Kollagenfibrillen zusammensetzte. Mit unserer neuen Rutheniumrotfärbung in der Kombination mit der Enzymverdauungsmethode wurde demonstriert, daß die Struktur mit Querstreifen und die Körnchen aus Chondroitinsulfat-Proteoglykan und/oder Glykoprotein besteht, und daß es sich bei der Struktur mit Querstreifen höchstwahrscheinlich um ein nichtkollagenes Aggregationsprodukt der Körnchen handelt, die eng an die parallel angeordneten, Hyaluronsäure-ähnlichen Fäden angelegt sind.
    Notes: Summary Systematic hyalinosis (juvenile hyaline fibromatosis) is characterized by hyalinized skin lesions. Electron microscopic examination of a hyalinized skin tumor from a 19-year-old man with this syndrome revealed that the hyaline was composed of ruthenium red-positive ultrastructures (granules, filaments, and a kind of cross-banded structure), indicating the presence of glycosaminoglycan or glycoprotein, and a small number of thin collagen fibrits. Using a new ruthenium red staining method combined with an enzymatic digestion procedure, it was demonstrated that the cross-banded structure and granules consisted of chondroitin sulfate-proteoglycan and/or glycoprotein, and that the cross-banded structure is probably a noncollageneous aggregate of the granules attached to the parallel-arranged filaments of hyaluronic acid-like nature.
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  • 34
    ISSN: 1432-069X
    Keywords: Kaposi's sarcoma ; Histochemistry ; Electron microscopy ; Venous capillary endothelium ; Angioblast ; Kaposi-Sarkom ; Histochemie ; Elektronenmikroskopie ; venöse Kapillarendothelien ; Angioblast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Histochemische und ultrastrukturelle Untersuchungen bei zwei Patienten mit Kaposi-Sarkom ergaben, daß die Spindelzellen die Merkmale von venösen Capillarendothelien aufweisen.
    Notes: Summary Histochemical and ultrastructural studies in two patients with Kaposi's sarcoma revealed that spindle cells have the pattern of venous capillary endothelium.
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  • 35
    ISSN: 1432-0533
    Keywords: Tangier disease ; Peripheral nerve ; Electron microscopy ; Cytometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A sural nerve biopsy was performed in a 55-year-old male patient with Tangier disease (familiallipoprotein deficiency). Light-microscopy showed an increase in the endoneural connective tissue and a loss of nerve fibers indicating a chronic peripheral neuropathy. Electron-microscopy revealed an accumulation of lipid droplets within Schwann cells of myelinated and unmyelinated nerve fibers. When compared with age-matched controls the myelinated fiber density was reduced with a relative preponderance of small myelinated fibers. In addition, distributional cytometric studies of nerve vibers in relation to the perineurium and endoneurial capillaries showed: Contrary to 4.6–7.5 μm thick nerve fibers, which accumulated in the center of the nerve fascicle, small (0.5–4.5 μm) and large (7.6–10.0 μm) fibers lay nearby the perineurium. The measured increase in small myelinated nerve fibers around endoneurial capillaries may be explained as a sign of regeneration.
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  • 36
    ISSN: 1432-0533
    Keywords: Human adenovirus 12 ; Hamsters ; Subcutaneous neuroblastomatous tumor ; T-antigens ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single subcutaneous inoculation of human adenovirus type 12 (Ad. 12), 0.05–0.1 ml of 108.0 TCID50 HEK cells/0.1 ml, was made on the back of 0-day-old hamsters. In 21 of 25 hamsters (84.0%), multiple solid tumors developed close to the inoculation site within 3 months. No control hamsters developed tumors. Tumor histopathology revealed the characteristic Homer Wright rosettes of neuroblastoma. Ad. 12-specific tumor antigens were demonstable in both the primary and the cultured tumor cells by the hnmunofluorescein technique. Histochemical demonstration of cholinesterase and NADH oxidoreductase gave rise to a predominantly positive intracytoplasmic granule within the tumor cells. Electron microscopy showed remarkably iniform cell morphology: small, undifferentiated neuroblastic cells with poorly developed intracytoplasmic organelles; many possessed characteristic solitary cilia in a 9+0 tubules pattern. Intercellular junctions were poorly developed. Search for an incipient tumor cell aggregate by means of immunofluorescein T-antigen detection was carried out through a 240-h period following Ad. 12 inoculation. A sequential study in parallel with electron microscopic examination of the normal subcutaneous tissue proved that neuroblastic cells closely associated with the muscle spindle anlage could preferentially become the most sensitive target for Ad. 12 tumorigenesis.
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  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 45 (1979), S. 241-245 
    ISSN: 1432-0533
    Keywords: Myelin formation ; Ganglioglioma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Formation of myelin sheaths by neoplastic cells was found in a spinal ganglioneuroma. All phases of initial myelination were observed including the formation of a mesaxonal spiral and the fusion of its famellae into a major dense line. A unique aspect of neoplastic myelin formation was the formation of sheaths around bundles of extracellular fibrils rather than axons or cell processes. Formation of myelin sheaths around extracellular material has never been observed before. The findings have implications on the mechanisms controlling initial myelination.
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  • 38
    ISSN: 1432-0533
    Keywords: Dog ; Canine distemper virus ; Cell fusion ; Demyelination ; Encephalomyelitis ; Immunofluorescence ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The early neuropathological development of demyelinating Canine Distemper Encephalomyelitis (CDE) was studied in SPF dogs. Neural tissues were examined up to 30 days post infection (PI). Three phases of activity were observed. The primary event (first observed 8 days PI) was a nonsuppurative encephalomyelitis associated with the initiation of central nervous system (CNS) infection by virus-laden lymphocytes. At 24 days PI noninflammatory demyelination occurred in well defined, subependymal foci. Cell fusion and syncytia formation accompanied this early demyelination. The third phase, found at day 30 PI in one dog showing signs of recovery, was a second wave of nonsuppurative inflammation. The initial encephalomyelitis was widely disseminated throughout the CNS but subsequent demyelination appeared to be initiated from within the ventricular system. Myelin was phagocytosed by endogeneous CNS macrophages often infected with Canine Distemper Virus (CDV). The possible importance of viral induced cell fusion as well as immune factors in the mechanism of demyelination are discussed.
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  • 39
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Pituitary adenoma ; Annulate lamellae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy revealed the presence of annulate lamellae in the cytoplasm of a heavily granulated prolactin cell adenoma that had been removed from a 34-year-old male patient presenting impotence. To our knowledge this is the third case of pituitary adenomas where annulate lamellae are reported.
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  • 40
    ISSN: 1432-0533
    Keywords: Progressive supranuclear palsy ; Neurofibrillary tangles ; Electron microscopy ; Straight filaments ; Twisted tubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of subcortical neurofibrillary tangles was investigated in pallidum, substantia nigra, periaqueductal gray, pontine reticular gray, and dentate nucleus of 5 autopsy cases of Progressive Supranuclear Palsy. Only tangles due to straight 150 Å wide filaments have been detected. These findings, obtained from a large series of cases and areas examined, confirm previous observations on the fine structure of neurofibrillary tangles in Progressive Supranuclear Palsy and suggest that the association between tangles due to straight filaments and tangles due to twisted tubules, so far described in one case, is probably exceptional.
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  • 41
    ISSN: 1432-0533
    Keywords: Childhood dermatomyositis ; Muscle biopsy ; Electron microscopy ; Tubular arrays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscle biopsies from 12 patients with a typical clinical picture of dermatomyositis have been examined by electron microscopy. Endothelial cells of intramuscular blood vessels, their basal lamina, pericytes, muscle fibers, and satellite cells show degenerative or regenerative alterations. In nine patients, tubular arrays were noted in the cisterns of endoplasmic reticulum of endothelial cells, pericytes, lymphocytes, macrophages and satellite cells. Other types of inclusions were also observed. The pathogenesis of the disease is discussed.
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  • 42
    ISSN: 1432-0533
    Keywords: Brain tumor cells ; Chemical carcinogen ; Benzo(a)pyrene ; Oncogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study was performed on normal and Benzo(a)-pyrene (B(a)P)-transformed fetal mouse brain cells. Early subcultures of a strain initiated from whole brain presented three cell types in vitro: astroglial, poorly differentiated glial, and spongioblastic types. After B(a)P-treatment, there was an exclusive transformation and the growth of neuroglia sometimes without gliofibrillary maturation, but with the presence of glial fibrillary acidic protein (GFAP) in the cytoplasm. Early subcultures of another strain initiated from cortex only presented poorly differentiated neuroglial cells. After transformation, cell maturation as evidenced by gliofibrillogenesis and GFAP production by these cells was observed. In both cases, the potentiality of glial differentiation after in vitro malignant transformation by a chemical carcinogen seemed preserved.
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  • 43
    ISSN: 1432-0533
    Keywords: Herpes simplex type 2 ; Herpes simplex encephalitis ; Cerebral metastasis ; Metastases and viral encephalitis ; Immunofluorescence ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 62-year-old woman developed neurologic deficits 7 months after pulmonary lobectomy for alveolar cell carcinoma of the lung. CT scan of the head demonstrated two metastases with marked peritumoral edema. Administration of Decadron, chemotherapy and 3,000 rad cranial radiation resulted in dramatic inprovement of dysphasia and right hand paresis. Almost 2 months later, rhythmic, involuntary movements of the left hand developed. There was progression to multifocal seizures, grand mal seizures, postictal depression, status epilepticus, and coma, with death 9 days after onset of the movement disorder. Bronchoalveolar carcinoma was widely disseminated in lungs and bones, and as three metastases in brain. Bland “ischemic” necrosis in a pseudolaminar pattern was present in the neocortex. Innumerable Cowdry type A intranuclear inclusion bodies were seen in neurons, astrocytes, and oligodendroglia. Immunofluorescence demonstrated Herpes simplex virus type 2 antigen and electron microscopy revealed virions with the morphology of the Herpes group. The case is significant for (1) the concurrence of intracranial metastases and Herpes simplex encephalitis, and (2) the causal agent, Herpes simplex virus type 2. The implication for the clinical neurocientist is the potential in a patient with systemic cancer, for the causation of neurologic complications by more than one factor or mechanism.
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  • 44
    ISSN: 1432-0584
    Keywords: Chronische myelo-monozytäre Leukämie ; Seeblaue Histiozyten ; Knochenmarksbiopsie ; Elektronenmikroskopie ; Chronic myelomonocytic leukemia ; Sea-blue histiocytes ; Bone marrow biopsy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Clinical data and light and electron microscopic findings are presented in a patient with chronic myelomonocytic leukemia of about 5 years' duration and no need for specific therapy. Cytogenetic studies failed to demonstrate a Philadelphia-chromosome. The leading clinical symptoms were anemia, moderate hepatomegaly, and leukocytosis with monocytes in the peripheral blood count. Light microscopy of bone marrow cores showed hypercellularity of neutrophil granulocytic and monocytic cell lines including some precursor forms. Electron microscopy confirmed the existence of a biphasic myelomonocytic cell proliferation with predominance of mature forms in both lineages; there were no gross cellular abnormalities and no “hiatus leukaemicus”. Conspicuous were cells of an undeterminated origin apparently neither belonging to the neutrophil granulocytic nor monocytic series and large histiocytic cells, possibly corresponding to the so-called sea-blue histiocytes of light microscopy. The high degree of maturation of both cell lines in the bone marrow is in accordance with the relatively benign and prolongated course of this rare type of leukemia.
    Notes: Zusammenfassung Von einem Patienten mit einer chronischen myelo-monozytären Leukämie von etwa 5 Jahren Dauer und ohne spezifische Therapie werden klinische sowie licht- und elektronenmikroskopische Befunde vorgestellt. Zytogenetische Untersuchungen ließen ein Philadelphia-Chromosom nicht erkennen. Die führenden Symptome waren eine geringe Anämie, eine mäßige Lebervergrößerung und Leukozytose mit Monozyten im peripheren Blutausstrich. Lichtmikroskopische Untersuchungen des Knochenmarkes zeigten eine Zellvermehrung der neutrophilen granulozytären und der monozytären Zellreihen einschließlich einiger Frühformen. Die Elektronenmikroskopie bestätigte das Vorhandensein einer biphasischen myelo-monozytären Zellproliferation mit Vorwiegen der reifen Formen in beiden Zellinien. Es bestanden keine bemerkenswerten zellulären Anomalien und kein „hiatus leucaemicus“. Auffallend waren Zellen unbestimmbarer Herkunft, die weder der neutrophilgranulozytären oder monozytären Reihe sicher zuzuordnen waren, und große histiozytäre Zellen, die wahrscheinlich den sogenannten „seeblauen Histiozyten“ der Lichtmikroskopie entsprechen. Der hohe Grad der Ausreifung in beiden Zellinien im Knochenmark steht in Übereinstimmung mit dem relativ gutartigen und langen Verlauf dieses seltenen Types einer Leukämie.
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  • 45
    ISSN: 1432-072X
    Keywords: R-Bodies ; Kappa particles ; Free-living hydrogen bacteria ; Induction ; Electron microscopy ; Chemical composition ; Defective prophages ; Plasmids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract R-Bodies have been found in a recently isolated pseudomonas-like free-living hydrogen oxidizing bacterium. Their isolation, fine structure and chemical composition are described and compared with the R-bodies from the kappa particles (Caedobacter), obligate endosymbionts of Paramecium aurelia. The 2K 1 R-bodies exhibited essential characteristics of the kappa R-bodies; however, their size and some other structural aspects proved that they represent a new type of R-bodies. The presence of phage tail-like particles in cells induced with Mitomycin C is in favour of the hypothesis that the R-bodies might be coded by defective prophages, or by extrachromosomal elements.
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  • 46
    ISSN: 1432-0711
    Keywords: Decidua ; Interzelluläre Verbindungen ; Gefrierätzen ; Elektronenmikroskopie ; Fibrinoid ; Decidua ; Intercellular junctions ; Freeze-fracturing ; Electron microscopy ; Fibrinoid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Cell contacts between developing decidual cells were examined in thin sections and in replicas of freeze-cleaved tissue of rat uterus. At the time of implantation only puncta adhaerentia were found between stromal cells. Gap junctions appeared 24 h after decidualization and thereafter increased in number and extent. Thus, there is little morphological evidence for a propagation of the initial stimulus for decidualization via gap junctions. An increase in amorphous, extracellular material is noted after decidualization with a concomitant decrease of collagen fibers. This amorphous material probably represents fibrinoid.
    Notes: Zusammenfassung Die Zellkontakte zwischen sich entwickelnden Deciduazellen wurden sowohl mit der Dünnschnittechnik als auch mit der Gefrierätzmethode im Rattenuterus untersucht. Zum Zeitpunkt der Implantation wurden nur Puncta adhaerentia zwischen Stromazellen gefunden. Nexus (gap junctions) erschienen 24 h nach Beginn der Decidualisierung und nahmen danach an Zahl und Größe zu. Diese morphologischen Befunde widersprechen der Ansicht, daß sich der initiale Reiz für die Decidualisierung der Stromazellen über Nexus ausbreitet. Nach der Decidualisierung wurde eine Zunahme von amorpher, extrazellulärer Substanz gleichzeitig mit einer Abnahme von Kollagenfasern gesehen. Diese amorphe Substanz stellt wahrscheinlich Fibrinoid dar.
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  • 47
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 123 (1979), S. 101-103 
    ISSN: 1432-072X
    Keywords: Bdellovibrio ; Cyanobacteria ; Marine sponges ; Symbiosis ; Infection ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A bdellovibrio-like bacterium was observed infecting unicellular symbiotic cyanobacteria in two coral reef sponges, Neofibularia irata and Jaspis stellifera. The infecting bacterium, which was located between the cell wall and the cytoplasmic membrane of the cyanobacteria, was similar in size and appearance to previously described bdellovibrios. This observation is believed to extend the host range of the bdellovibrios.
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  • 48
    ISSN: 1432-069X
    Keywords: Fibronectin ; Skin ; Basement membranes ; Immunohistochemistry ; Electron microscopy ; Fibronectin ; Haut ; Basalmembran ; Immunohistochemie ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Verteilung des extracellulären Glykoproteins Fibronectin im Haut- und Zungengewebe der Ratte wurde unter Verwendung von spezifischem Antiserum licht- und elektronenmikroskopisch mit Hilfe der Immunofluorescenz- und Immunoperoxidasemethoden untersucht. Aus den Ergebnissen schließen wir, daß Fibronectin weder in stabilen, differenzierten Gewebeteilen wie Talgdrüsen, Matrix, Mark, Rinde oder Cuticula des Haares oder der inneren und äußeren Haarwurzelscheide, noch in Geweben, in denen die Zellen zum Teil beweglich sind (z. B. Epidermis), vorkommt. Es ist aber charakteristisch für Zonen, wo Zellteilung in Berührung mit einem extracellulären Gerüst vor sich geht, wie z. B. an einer Basalmembran oder in lockerem Bindegewebe. Auffallende Beispiele waren die mit Follikelepithelien verbundene Hyalinmembran und Bindegewebsscheide, die unter Gefäßendothelzellen liegende Basalmembran, die Bindegewebe, welche die Nerven- und Muskelfaserbündel umgeben und durchsetzen und das Bindegewebe der Dermis. Im letzteren Falle war das Fibronectin oft mit Kollagenfasern eng verbunden. In der Basalmembran an der Grenze zwischen Dermis und Epidermis war Fibronectin an der Plasmamembran der basalen Zellen und im Gebiet der Lamina lucida zu finden. Es bestand kein Zusammenhang mit spezifischen Stellen der Zellen-Substrat-Adhäsion wie den Hemidesmosomen. Das endoplasmatische Reticulum der Fibroblaste ließ sich stark färben — ein Hinweis, daß diese Zellen einen wichtigen Ort der Synthese darstellen.
    Notes: Summary Specific antiserum was used to investigate the distribution of the extracellular glycoprotein, fibronectin, in rat skin and tongue tissue by light and electron microscopy with immunofluorescence and immunoperoxidase techniques. We conclude that fibronectin is absent from stable, differentiated parts of tissues, such as the sebaceous glands or the matrix, medulla, cortex, and cuticles of the hair and the inner and outer root sheaths, or even in tissues in which there is some cell movement, such as the epidermis. It is, however, characteristic of sites at which cell division is occurring in contact with an extracellular scaffolding, such as basement membrane or loose connective tissue. Conspicuous examples were in the glassy membrane and connective tissue sheath associated with the follicular epithelium, the basement membrane underlying vascular endothelial cells, the connective tissues surrounding and investing nerve and muscle fibre bundles, and the dermal connective tissue where fibronectin was often associated closely with collagen fibres. At the basement membrane of the dermal/epidermal junction, fibronectin occurred at the plasma membrane of the basal cells and in the lamina lucida area. There was no correlation with specific areas of cell-substrate adhesion, such as the hemidesmosomes. The endoplasmic reticulum of fibroblasts stained strongly suggesting that these cells represent a major site of synthesis.
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  • 49
    ISSN: 1432-072X
    Keywords: Acetobacter suboxydans ; Bacteriophage A-1 ; Restriction ; Modification ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A bacteriophage ofAcetobacter suboxydans was isolated and found to correspond to type A phage according to Bradley's classification. The phage contains double stranded DNA. The length of the latency period and burst size could not be precisely determined because of apparent non-synchronous release of phage from single infective cycles. The host range was determined using 24 strains ofAcetobacter andGluconobacter species. Evidence for a probable occurence of host determined restriction and modification was obtained withAcetobacter suboxydans strain ATCC 621. The phage is designated A-1 and it is the first one to be reported forAcetobacter.
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  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 265 (1979), S. 91-99 
    ISSN: 1432-069X
    Keywords: Electron microscopy ; Civatte body ; Atrophy ; Light sensitivity ; Heredity ; Elektronenmikroskopie ; Civatte-Körperchen ; Atrophie ; Lichtempfindlichkeit ; Vererbung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zwei Patienten (insgesamt 4), zwei Brüder, mit »The diffuse and macular atrophic dermatosis» wurden beobachtet. Das familiäre Vorkommen, die «peau citréine»-Plaquen an der dorsalen Seite des Rumpfes, sowie eine kongenitale Phimose mit einer oberflächlichen Atrophie des Glans Penis, sind die neuen Befunde. Licht- und elektronenmikroskopische Befunde einer «peau citréine»-Plaque und einer erythematösen, skleroatrophischen Plaque werden geschildert. Es wurde auch gezeigt, daß die elastischen, färbungspositiven kugelähnlichen Strukturen, die in ungewöhnlich großer Zahl in der oberen Dermis gefunden wurden, fortgeschrittenere transformierte Civatte-Körperchen darstellen, die epidermale Zellen enthalten.
    Notes: Summary Two brothers with the “diffuse and macular atrophic dermatosis” making a total of 4 patients are reported. The familial occurrence, numerous large “peau citréine” plaques situated on the dorsum of the upper trunk and congenital phimosis with superficial atrophy of glans penis, represent the additional features reported. The light and electron microscopic findings of the least affected site on the arm, of a “peau citréine” and of an erythemoscleroatrophic plaque, none previously studied, have been reported. Among other items, it was also found that the elastic stain-positive globe-like structures found in an unusually large number throughout the edematous upper dermis represent more advancely transformed “Civatte bodies” containing epidermal filamentous cell material.
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  • 51
    ISSN: 1434-4726
    Keywords: Dünnschnittmethode ; Gefrierbruchmethode ; Elektronenmikroskopie ; Zellverbindungskomplexe ; Perilymphatisches Gewebe ; Thin-section method ; Freeze-fracture method ; Electron microscopy ; Junctional complexes ; Perilymphatic tissue
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The perilymphatic tissue covering the bony labyrinthine capsule was studied in chinchillas by help of the thin-section and the freeze-fracture methods. Among the extremely flat and extended cells there were demonstrated fasciae occludentes and maculae communicantes. It is supposed that the perilymphatic tissue is arachnoidal tissue, too.
    Notes: Zusammenfassung Mit Hilfe der Dünnschnitt- und Gefrierbruchmethode wurde das perilymphatische Gewebe, das die knöcherne Labyrinthkapsel deckt, an Chinchillas untersucht. Zwischen den extrem flachen, ausgedehnten Zellen fanden sich Fasciae occludentes und Maculae communicantes. Es wird vermutet, daß das perilymphatische als arachnoidales Gewebe anzusehen ist.
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  • 52
    ISSN: 1434-4726
    Keywords: Eighth nerve ; Inner ear ; Human ; Fluorescence microscopy ; Electron microscopy ; Menière ; Neurilemoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fluorescence microscopy was used to examine the adrenergic, bloodvessel-independent innervation of the 8th nerve and inner ear specimens in patients with otoneurological diseases. Specifically fluorescent adrenergic axons were scantily seen among the myelinated nerve fibers in the 8th nerve and in the subepithelial regions of the end organs but not in the endolymphatic sac.
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  • 53
    ISSN: 1432-0827
    Keywords: Parathyroid hormone ; Osteoclasts ; Electron microscopy ; Morphometry ; Metaphysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effects of parathyroid hormone (PTH) on the size of the osteoclasts, nuclei, ruffled borders, and clear zones in long bones of thyroparathyroidectomized (TPTX) rats were quantitated as a function of time. These data were compared with the number of osteoclasts in the bone and with plasma calcium levels. A significant increase in the average size of the ruffled borders was demonstrated 30 min after injection of 50 U of purified bovine PTH, and of the clear zones 30–90 min after PTH. This was followed at 90 min by an increase in the average size of the cells. The sizes of ruffled borders and clear zones dropped sharply to control levels after 6 h, whereas the size of the cells remained elevated up to 12 h and returned to control values at 24 h. Plasma calcium levels were increased, but not significantly, between 30 min and 6 h. An increase in the number of osteoclasts was significant after 12 h. Removal of the parathyroid glands did not diminish the normal activity of osteoclasts. In animals with intact glands injection of 50 U of PTH did not cause a significant change in cell size or resorbing apparatus. It is concluded that PTH acts to rapidly stimulate the bone resorptive activity of osteoclasts and to cause a delayed increase in their number.
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  • 54
    ISSN: 1432-0827
    Keywords: Osteon ; X-ray diffraction ; Pole figures ; Electron microscopy ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The X-ray diffraction method based on pole figures has been applied to single osteon samples in order to obtain information about the texture of the inorganic bone fraction and the way it changes during calcification. The osteon samples were cylindrically shaped, with axes corresponding to those of the haversian canals. Selection was carried out according to the degree of calcification and the orientation of collagen bundles and inorganic particles. Osteons at both the initial and final stages of calcification were chosen. Arrangements of fiber bundles and inorganic particles in successive lamellae characteristic of three types of osteons were selected: longitudinal, alternate, and transversal. The results indicate that in all three types of osteons, the long axis of the sample is apparently the only direction of orientation because the transversally oriented crystallites give an isotropic diffuse scattering as would be expected if all the inorganic particles were irregularly oriented around the osteon axis. The number of longitudinally oriented crystallites increases progressively from transversally oriented osteons to alternately and longitudinally oriented ones. The crystallite orientation in an axial direction increases in fully calcified osteons. This last result is in agreement with the electron microscopic finding that the long needle-shaped crystallites covering much more than a major collagen period and measuring 40–45 Å in width increase in number as calcification proceeds.
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  • 55
    ISSN: 1432-1335
    Keywords: Telangiectatic osteosarcoma ; Histogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recent investigations have shown that telangiectatic osteosarcoma has a poorer prognosis than other osteosarcomas. To elucidate the histogenesis of TOS two cases were investigated on the electron microscopic level. The results show that besides anaplastic, osteoblast-like, and fibroblast-like tumor cells angiosarcomatous components can be observed in this malignant bone tumor, which are characterized by endothelial cells with pinocytotic vesicles, tight intercellular junctions, fine fibrils, and so-called Weibel-Palade bodies in their cytoplasm. From these results, it is concluded that telangiectatic osteosarcoma is derived from multipotent mesenchymal cells with potential differentiation into various directions, such as osteoblast-like cells, endothelial cells, and fibroblast-like cells.
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  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 57 (1979), S. 641-646 
    ISSN: 1432-1440
    Keywords: Mitochondria ; Membranes ; Cytochrome oxidase ; Fluorescence methods ; Electron microscopy ; Mitochondrien ; Membranen ; Cytochromoxidase ; Fluoreszenzmethoden ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Biologische Membranen sind im wesentlichen asymmetrische zwei-dimensionale Lösungen von Proteinen in einer bimolekularen Lipidschicht. Das allgemeine Aufbauprinzip und viele physikalische Eigenschaften biologischer Membranen lassen sich dadurch erklären, daß sowohl die Membranproteine als auch die Membranlipide hydrophile und hydrophobe Stellen besitzen. Die meisten biologischen Eigenschaften einer Membran werden durch die Membranproteine bestimmt, die richtungsgebundene Prozesse katalysieren können. Anhand des Membranproteins Cytochromoxidase wird gezeigt, wie die räumliche Anordnung von Membranproteinen durch chemische, fluorometrische und elektronenoptische Methoden studiert werden kann. In den meisten Fällen ist es allerdings heute noch nicht möglich, die Funktionen einer Membran aufgrund ihres molekularen Bauprinzips zu erklären.
    Notes: Summary Biological membranes are essentially asymmetric two-dimensional solutions of proteins in a bimolecular lipid layer. The overall structure and many physical properties of biological membranes can be explained by the fact that membrane proteins and membrane lipids contain hydrophilic as well as hydrophobic domains. Most biological properties of the membrane are determined by the membrane proteins which can catalyze directional processes. With the membrane protein cytochrome oxidase it will be demonstrated how the three-dimensional arrangement of membrane proteins can be studied by chemical, fluorometric, and electron optical methods. However, it is in most cases still impossible to explain the function of a membrane on the basis of its molecular architecture.
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  • 57
    ISSN: 1432-1440
    Keywords: Menschliches Plasma ; DNS ; Elektronenmikroskopie ; Konzentration ; Human plasma ; DNA ; Electron microscopy ; Concentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The DNA content in plasma of five healthy human individuals has been estimated. Structures ascertained by electron microscopy have been identified as double-stranded DNA. Depending on the isolation procedure applied the DNA molecules found may originate from free and/or complexed forms of DNA. The lengths range from less than 0.2 µm up to about 13 µm. DNA concentration is in the range of 3 to 11 ng/ml.
    Notes: Zusammenfassung Es wurde der DNS-Gehalt im Plasma fünf gesunder Testpersonen ermittelt. Elektronenmikroskopisch darstellbare Strukturen konnten als doppelsträngige DNS charakterisiert werden. Bedingt durch die Isolierungsmethode resultiert die gefundene DNS sowohl von freier und/oder DNS, die in komplexierter Form im Plasma vorliegt. Die Moleküllängen variieren von weniger als 0,2 µm bis zu ca. 13 µm. Die Konzentration liegt im Bereich von 3–11 ng DNS/ml.
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  • 58
    ISSN: 1432-1246
    Keywords: Electron microscopy ; Morphometry ; Freeze etching ; Liver ; Aging ; Polychlorinated biphenyls ; Elektronenmikroskopie ; Morphometrie ; Gefrierätzung ; Leber ; Altern ; polychlorierte Biphenyle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der vorliegenden Untersuchung wurden jungen und alten männlichen Wistarratten polychlorierte Biphenyle (PCB) i.p. appliziert. Die altersbedingten und die hepatotoxischen Veränderungen in der Leber wurden licht- und elektronenmikroskopisch erfaßt. Des weiteren wurden Membranveränderungen mit der Gefrierätzung nachgewiesen. Neben den altersbedingten Veränderungen im Vergleich der beiden Kontrollkollektive fällt vor allem die exzessive Proliferation des glatten endoplasmatischen Retikulums auf, welche nach PCB-Applikation in den Hepatocyten nachzuweisen ist. Bei den jungen Ratten betrug die Vermehrung der Oberflächen-dichte dieser Membranen im Vergleich zu den Kontrolltieren 803% (P〈0,001) und bei den alten Ratten 282% (P〈0,001). Bei alten anderen untersuchten Parametern wurden sowohl bei den jungen als auch bei den alten Ratten statistisch signifikante Verringerungen nach PCB-Gabe festgestellt.
    Notes: Summary Thin-section and freeze-fracture techniques have been employed to investigate the ultrastructure of PCB-intoxicated rat liver of different ages. Besides alterations in the supramolecular structure of the plasma membranes, excessive proliferation of smooth endoplasmic reticulum (SER) in the hepatocytes was observed. In young rats, the surface density increased by up to 803% (P〈0.001) and in old rats up to 282% (P〈0.001) compared with the control rats. All other investigated parameters decreased significantly after the application of PCB.
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  • 59
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 381 (1979), S. 127-135 
    ISSN: 1432-2013
    Keywords: Na+−K+-ATPase ; Rat kidney ; Electron microscopy ; Substructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purified membrane-bound Na+−K+-ATPase from rat kidney outer medulla was studied by freeze-fracturing, by freeze-etching and by negative staining. Freeze-fracturing of purified Na+−K+-ATPase membranes shows intramembraneous particles with a diameter of about 100 Å. The frequency of these intramembraneous particles — as estimated from the particle densities on the two fracture faces — lies between 4700 and 5600 particles per μm2. Applying rotary shadowing a four partite substructure could be detected in these intramembraneous particles observed on the fracture planes. The same four partite substructure was detected in particles observed on freeze-fractured and rotary shadowed intact baso-lateral plasma membranes of the thick ascending limb of Henle's loop. Particles could be also detected on both membrane surfaces of the purified Na+−K+-ATPase. These surface particles have about the same diameter and are present at about the same frequency as those observed within the freeze-fractured membranes. Negative staining of isolated Na+−K+-ATPase membranes showed particles on both membrane surfaces with a diameter between 30 and 50 Å, at a frequency of about 19,000 per μm2. On aspects of membrane edges we observed structures which suggest a transmembraneous connection of the negatively stained particles on both membrane surfaces. Our results suggest that the Na+−K+-ATPase protein is composed of four units and that each unit spans the cell membrane. The native enzyme structure of the Na+−K+-ATPase protein seems to be preserved during freeze-fracturing and freeze-etching. It is proposed that the four enzyme units of the Na+−K+-ATPase complex are dissociated during the negative staining procedure.
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  • 60
    ISSN: 1432-0878
    Keywords: Fat body ; Calliphora ; Electron microscopy ; Cytochemistry ; Ecdysterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the larval fat body of Calliphora erythrocephala, protein accumulation and autophagic activity occur prior to the onset of puparium formation. The involvement of the lysosomal system in the degradation of sequestered protein and cell organelles can be demonstrated by the electron microscopical cytochemical localization of the lysosomal marker enzyme acid phosphatase in so-called protein granules. These granules contain not only newly synthetized or absorbed protein but also remnants of cell organelles such as mitochondria and endoplasmic reticulum. Ligation of the larvae behind the brain-ring gland complex prevents the appearance of these acid phosphatase positive granules. They can be induced in ligated larvae by the injection of 20 hydroxyecdysone into the abdomen. These findings are briefly discussed in relation to the role of moulting hormones in normal development, especially with regard to the induction of autophagic activity.
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  • 61
    ISSN: 1432-0878
    Keywords: Lipid absorption ; Pyloric caeca ; Electron microscopy ; Feeding experiment ; Rainbow trout
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rainbow trout were killed 4 and 18 h after being fed wax ester-rich marine Zooplankton and the absorptive epithelium of the pyloric caeca examined by electron microscopy. Numerous osmiophilic drops were seen in the lamina propria underlying the epithelium of fish killed at both times, but these drops were only abundant within columnar epithelial cells of fish killed 4 h after feeding. Pinocytotic profiles were not common at the luminal plasma membranes, nor were osmiophilic droplets seen in the terminal web area between the luminal plasma membrane and the extensive smooth endoplasmic reticulum. Numerous osmiophilic droplets, 30–100 nm in diameter, were present in the cisternae of the smooth endoplasmic reticulum with up to five separate droplets per individual cisterna. Columnar epithelial cells also contained up to 100 large osmiophilic drops (“conglomerates”) which tended to be concentrated in the supranuclear (Golgi) regions. The conglomerates were 250–1200 nm in diameter and were themselves made up of smaller droplets 30–400 nm in diameter. Conglomerates were present both within intracellular membranes and free in the cytoplasm. Osmiophilic droplets in the intercellular spaces and lamina propria were similar in size to individual droplets within conglomerates. We conclude that triacylglycerols are elaborated in the smooth endoplasmic reticulum, transferred to and processed in the Golgi region and finally discharged serosally as chylomicron-like particles of not greater than 400 nm diameter.
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