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  • Electronic Resource  (1,083)
  • 1985-1989
  • 1975-1979  (1,083)
  • 1965-1969
  • 1979  (1,083)
  • Life and Medical Sciences  (731)
  • Engineering General  (228)
  • Electron microscopy  (100)
  • Bone
  • Electron Microscopy
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  • Electronic Resource  (1,083)
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  • 1985-1989
  • 1975-1979  (1,083)
  • 1965-1969
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  • 1
    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.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 384 (1979), S. 159-172 
    ISSN: 1432-2307
    Keywords: Myxoid liposarcoma ; Histogenesis ; Electron Microscopy ; Hibernoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ten myxoid liposarcomas (ML) were studied ultrastructurally in an attempt to determine the histogenesis of this neoplasm and structural associations which might contribute to their relatively benign clinical behavior. The findings were compared with normal and neoplastic adipose tissue. Three cell types were observed, i.e., “primitive” mesenchymal cells, intermediate cell types, and lipoblasts at various stages of development. The principle differences between the lipoblastic elements were the number and the size of intracytoplasmic fat vacuoles, the development of basement membrane-like material, micropinocytotic vesicles along the plasma membrane and the quantity and pleomorphism of mitochondria. The tumor vasculature was complex but consistently demonstrated a multilayered basal lamina. This finding has been described in neoplasms associated with a relatively good prognosis. This study demonstrates that the better differentiated lipoblasts in ML share some features with normal brown fetal fat and hibernoma. It is, thus, suggested that ML may be derived from brown adipose tissue.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 224 (1979), S. 17-23 
    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.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of gynecology and obstetrics 227 (1979), S. 103-117 
    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.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 27 (1979), S. 177-185 
    ISSN: 1432-0827
    Keywords: Calcification ; Bone ; Glycoprotein ; Golgi ; Osteoblasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The elaboration of bone matrix glycoprotein by osteoblasts of alveolar bone was investigated by radioautography after the intravenous injection of3H-fucose into young rats. At selected times after injection, animals were sacrificed by intracardiac perfusion and demineralized specimens were prepared for light and electron microscope radioautography. At 5 and 10 min after injection, when the blood fucose level was high, silver grains were restricted to the spheroidal and cylindrical saccules of the Golgi apparatus. At 20 min membrane-limited secretory granules were also labeled. By 35 min, the blood fucose level had dropped and silver grains were detected over the apical cortical cytoplasm, in association with secretory granules located therein. Some grains were present over osteoblast processes and the adjacent prebone matrix. By 4 h most of the silver grains had left the cell. At that time they were observed over prebone, adjacent to osteoblast processes, as well as over the prebone-bone junction where a distinct band of label was noted. In demineralized preparations an electron-dense granular material was present at the prebone-bone junction in association with collagen fibrils. These findings provide evidence that osteoblasts in alveolar bone synthesize fucose-containing glycoprotein and indicate that the addition of3H-fucose occurs in the Golgi apparatus. The glycoprotein passes to the apical cortical cytoplasm by way of membrane-limited secretory granules, is exteriorized, and accumulates at the site where prebone transforms into bone (the prebone-bone junction). Since this is also the site of the calcification front, the deposition of labeled glycoprotein may be related to the deposition of bone mineral.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 27 (1979), S. 95-99 
    ISSN: 1432-0827
    Keywords: Bone ; Fluoride ; Analysis ; Food ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Recently published bone fluoride values from Iowa are very high compared to earlier reports, suggesting an increase in fluoride intake. Reanalysis of the Iowa specimens shows levels one-fourth those reported by the Iowa laboratory indicating an error in the original report. Seventeen bone specimens, collected from long-term residents of Rochester, New York, drinking 1 ppm F− water, had a mean value of 2085±270 ppm F− on an ashed-weight basis. This value is not significantly different from that predicted by the data of Zipkin et al. in 1958. These data, therefore, do not support the contention that there has been an increase in fluoride intake.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 28 (1979), S. 103-105 
    ISSN: 1432-0827
    Keywords: Bone ; Photodensitometry, X-ray ; Radiography ; Spectrophotometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A conventional spectrophotometer was used to do radiographic photodensitometry of bone mass. An experiment to produce osteoporosis in guinea pigs required quantification of changes in bone mass. Lack of a densitometer necessitated finding another method for quantification. The method developed involved using industrial film in a closed X-ray system. Optical density of X-rays was then read in a spectrophotometer at nine femur locations. Highly significant correlations between optical density and femur calcium content and femur dry weight per millimeter were obtained. Histological sections from an animal with low optical density measurements confirmed bone loss by showing decreased cortical width and loss of trabecular bone. In addition to using readily available equipment, this method offers the advantage of being able to detect bone loss in specific areas of the bones. In addition, bones are left intact and can be used for other purposes.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-0827
    Keywords: ESR ; Bone ; Enamel ; CO3-Apatite ; Paramagnetism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Carbonate-containing hydroxyapatite, enamel, and bone were irradiated by an X-ray and investigated between 77° and 350°K by means of electron spin resonance (ESR) spectroscopy. The ESR spectrum of enamel irradiated at 77°K in vacuum and observed at the same temperature was almost the same as that of the carbonate-containing hydroxyapatite. The temperature dependence of signal intensities confirms a spin-energy exchange between the mineral and organic constituents in bone, but in enamel no or very little spinenergy exchange between the mineral and organic constituents. Considerable similarity among the ESR spectra of enamel, bone, and carbonate-containing apatite was obtained after X-ray irradiation in air at 300°K with both an X-band and a Q-band ESR spectrometer. The Q-band spectrum can be interpreted in terms of two paramagnetic species. One is identified as a CO 3 3− anion radical which has an axial symmetry withg factors of 2.0029 and 1.9972. The other species is found to be centered atg=2.0019.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 28 (1979), S. 33-36 
    ISSN: 1432-0827
    Keywords: Infrared, visible light ; Bone ; Collagen ; Apatite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Photovoltaic effect (infrared and visible light) is observed in bone and its two major components, collagen and apatite, at room temperature. A dimunition in the magnitude of photovoltage is observed after exposure to ultraviolet light in all the cases. The drift mobility of the charge carriers is obtained by measuring I versus V relationships in sandwich samples and relating them to the permitivity of the medium. Lifetime of the injected carriers is measured in the usual way. The data are consistent with the hypothesis that the effects are due to protonic conduction phenomena.
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  • 10
    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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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 34 (1979), S. 201-215 
    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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  • 12
    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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  • 13
    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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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 4 (1979), S. 72-78 
    ISSN: 1432-2161
    Keywords: Sarcomas ; Bone ; Neoplasms ; Radiation induced
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Historically, the literature reveals that the incidence of radiation induced bone sarcomas is very low. Details related to epidemiology cannot be identified, however, because of the difficulty of identifying precisely the patient population at risk for development of the radiation induced sarcoma. The change in character of practice in cancer management with ever increasing numbers of patients receiving both radiation therapy and chemotherapy should alert physicians to the potential for increased incidence of this rare and unusual tumor.
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  • 15
    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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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 383 (1979), S. 167-179 
    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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  • 17
    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.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 155 (1979), S. 209-219 
    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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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 157 (1979), S. 121-132 
    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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  • 20
    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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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 158 (1979), S. 51-62 
    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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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 45 (1979), S. 53-59 
    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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  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 45 (1979), S. 133-140 
    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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  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 46 (1979), S. 1-10 
    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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  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 46 (1979), S. 25-32 
    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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  • 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
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    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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  • 28
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    Acta neuropathologica 47 (1979), S. 1-11 
    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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  • 29
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    Acta neuropathologica 47 (1979), S. 237-240 
    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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  • 30
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    Acta neuropathologica 48 (1979), S. 113-125 
    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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  • 31
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    Anatomy and embryology 155 (1979), S. 23-36 
    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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  • 32
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    Archives of dermatological research 266 (1979), S. 253-267 
    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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  • 33
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    Archives of dermatological research 266 (1979), S. 295-310 
    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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  • 34
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    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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  • 35
    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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  • 36
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    Acta neuropathologica 48 (1979), S. 219-221 
    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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  • 37
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    Archives of dermatological research 265 (1979), S. 195-206 
    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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  • 38
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    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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  • 39
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    Annals of hematology 39 (1979), S. 177-190 
    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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  • 40
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    Acta neuropathologica 45 (1979), S. 187-194 
    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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  • 41
    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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  • 42
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    Acta neuropathologica 47 (1979), S. 205-211 
    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
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    Acta neuropathologica 46 (1979), S. 239-241 
    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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  • 44
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    Acta neuropathologica 47 (1979), S. 189-196 
    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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  • 45
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    Acta neuropathologica 47 (1979), S. 61-66 
    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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  • 46
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    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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  • 47
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    Acta neuropathologica 46 (1979), S. 163-166 
    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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  • 48
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    Acta neuropathologica 47 (1979), S. 55-59 
    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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  • 49
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    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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  • 50
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    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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  • 51
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    Acta neuropathologica 45 (1979), S. 147-152 
    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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  • 52
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    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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  • 53
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    Acta neuropathologica 47 (1979), S. 163-165 
    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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  • 54
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    Calcified tissue international 27 (1979), S. 33-40 
    ISSN: 1432-0827
    Keywords: Chick embryo ; Bone ; Organ culture ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The study describes the ultrastructure of the mineralized portion of chick tibiae from 10 days in ovo to 2 days post-hatch. At 10 days a single mineralized cylinder surrounds the diaphysis. On its outer surface columnar trabeculae join to form ridges parallel to the long axis of the bone. These ridges are covered by another cylinder and form the haversian canals. At 11 days vascular invasion of the marrow cavity occurs and resorption of the endosteal surface begins. This type of periosteal deposition and endosteal resorption is repeated during and subsequent to embryonic development. The mineralized portion of 10-day chick tibiae cultured for 2 days in modified BGJ medium was compared with 10-, 11-, and 12-day tibiae in ovo. Cultured tibiae were similar in length and calcium content to 11-day tibiae in ovo. The form of mineral deposited in ovo and in culture was the same, namely, aggregates of spherical mineral clusters. Differences in culture included the following: (a) few concentric cylinders were deposited as compared with tibiae in ovo; (b) trabeculae were not arranged in rows and ridges in culture; (c) osteocytic lacunae were restricted to bases of trabeculae rather than uniformly distributed as in ovo; and (d) the endosteal surface of tibiae in culture appeared etched.
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  • 55
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    Calcified tissue international 27 (1979), S. 57-64 
    ISSN: 1432-0827
    Keywords: Bone ; Bone formation ; Calcification ; Calcification nodule ; EM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Osteolathyrism has been used as an experimental model for the study of calcification nodules during the mineralization process. Periosteal exostoses developing in osteolathyrism characteristically have spherical basophilic structures (calcification nodules) in the vicinity of developing bone spicules. In thin sections, the nodules were seen scattered between collagen fibers in the intercellular matrix. Collagen fibers did not appear to be present within the nodules but sometimes were packed just outside them. Matrix vesicles were also present in areas of early mineralization. After EDTA decalcification, the majority of the nodules consisted of a fine granular material surrounded by an electron-dense peripheral zone. The peripheral dense zone was occasionally incomplete in small nodules in areas of early mineralization. An electron-dense central area could be observed in the center of the nodules. Evidence has been presented indicating that the calcification nodules arise from smaller mineralization foci, presumably matrix vesicles. The calcification nodules enlarge to approximately 1.0 µm in size, at which point development is slowed or halted allowing the formation of the peripheral dense zone. Although coalescence of nodules was observed, this was more a random event. The further mineralization of the trabeculae was achieved by the calcification of the collagen fibers. The mineralized trabeculae reflected this pattern of nodular and collagenous calcification. It is suggested that this pattern of calcification is characteristic of rapidly developing woven bone.
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  • 56
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    Calcified tissue international 27 (1979), S. 105-108 
    ISSN: 1432-0827
    Keywords: Bone ; Femur ; Strength ; Density ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In order to ascertain whether the intrinsic strength of human bone changes with age or not, we have determined the ultimate tensile strength and density of strips of femoral cortical bone. These femora were collected from cadavers varying in age from 13 to 97 years. The results show that both density and intrinsic strength of bone increase up to about the fourth decade of life and then decrease with age. However, the rate of decrease of strength is greater than that of density. This indicates that the density of bone is not the sole determining factor of its strength, and that some other factors play an important part.
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  • 57
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    Keywords: Bone ; Rickets ; Hypophosphatemia ; Microradiography ; D-resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The perilacunar areas of low mineral density in microradiographs from cortical bone of patients with hypophosphatemic (vitamin D-resistant) rickets are not evenly distributed throughout the bone tissue. Their frequency and distribution were determined in bone from 9 patients with this disease. It was found that the lesion was more frequent in haversian bone than in interstitial bone, and along the inner circumference of growing haversian systems as compared with the outer circumference. These findings indicate that the lesion is the result of retarded mineralization, and that mineralization slowly proceeds in these areas as the bone becomes older. A relatively high frequency of the lesion was also found in osteons with an elliptical cross section along the long axis of the ellipse. The cause of the abundance of the lesion at these sites is not clear, but it is possible to explain the uneven distribution in elliptical osteons by assuming an unequal rate of bone formation in these structures.
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  • 58
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    Calcified tissue international 27 (1979), S. 165-169 
    ISSN: 1432-0827
    Keywords: Oxygen uptake ; Bone ; Oxygen tension ; Carbon dioxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The present study was carried out to determine the influence of carbon dioxide and oxygen tension on the respiratory activity of bone cells in mouse calvaria in vitro. Five-day-old mouse calvaria were removed aseptically and incubated individually for 1 h at 37° C in a closed reaction chamber containing 1.5 ml of tissue culture medium made up of 60% horse serum in Gey's solution containing 100 unit/ml penicillin and 100µg/ml streptomycin. Before the calvaria were added, the medium in the incubation chamber was equilibrated with 10%, 20%, 30%, or 50% oxygen balanced with nitrogen. The effect of CO2 on oxygen utilization by the calvaria was determined by incubating the calvaria in a medium previously equilibrated with either 50% O2 balanced with N2 or 50% O2 and 5% CO2 balanced with N2. At each oxygen tension, the rate of oxygen utilization by the calvaria was measured polarographically by a Clark oxygen electrode. The results showed that the rate of oxygen uptake of bone increased as the oxygen tension increased and carbon dioxide stimulated significantly the rate of oxygen utilization by the bone cells. In view of the previous reports that both carbon dioxide and oxygen tension are implicated in the process of bone resorption, it is suggested that these two factors may affect bone resorption by influencing the oxygen utilization by bone cells and ultimately controlling their energy metabolism.
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  • 59
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    Calcified tissue international 28 (1979), S. 37-42 
    ISSN: 1432-0827
    Keywords: X-ray diffraction ; Hydroxyapatite ; Whitlockite ; Fish (Pisces) ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Pyrolyzed scales, fin spines, and bone from the ray-finned bony fishPolypterus (Actinopterygii) showed two mineral phases on X-ray diffraction: hydroxyapatite (HA), Ca5(PO4)3OH, and whitlockite, Ca3(PO4)2. The ratio of HA/whitlockite varied with the structure (scale, spine, bone) within each individual fish. The relative proportions of HA to whitlockite in pyrolyzed samples reflected the Ca/P ratio of the sample. Whitlockite appears after pyrolysis when the Ca/P is lower than 1.67. Among the five fish investigated, for each structure a general trend was noted. The proportion of HA relative to whitlockite increased with size (age) of the fish. Thus the smallest fish, a juvenile, exhibited a low Ca/P mineral in its calcified tissues, whereas the larger fish had progressively more HA and less whitlockite.
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  • 60
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    Calcified tissue international 28 (1979), S. 17-22 
    ISSN: 1432-0827
    Keywords: Anticonvulsant ; Ketogenic diet ; Calcium ; Vitamin D ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Vitamin D and mineral metabolism status was examined in five children maintained chronically on combined ketogenic diet-anticonvulsant drug therapy (KG), and the results compared to those obtained in 18 patients treated with anticonvulsant drugs alone (AD) and 15 normal controls. KG patients exhibited biochemical findings of vitamin D deficiency osteomalacia: decreased serum 25-hydroxyvitamin D (25OHD) and calcium concentrations, elevated serum alkaline phosphatase and parathyroid hormone concentrations, decreased urinary calcium and increased urinary hydroxyproline excretion, and decreased bone mass. Although the KG and AD groups demonstrated similar reductions in serum 25OHD concentration, the KG patients exhibited a significantly greater reduction in bone mass. In response to vitamin D supplementation (5000 IU/day), mean bone mass in the KG group increased by 8.1±0.9% (P〈0.001) over a 12-month period. These results suggest that ketogenic diet and anticonvulsant drug therapy have additive deleterious effects on bone mass and that these effects are partially reversible by vitamin D treatment.
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  • 61
    ISSN: 1432-0827
    Keywords: Bone ; Bone cells ; Cyclic AMP ; Osteoclast activating factor ; Lymphokine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Osteoclast activating factor (OAF) is a lymphokine which may participate in the pathologic destruction of bone observed in a number of disorders. In the current studies, we investigated the action of OAF on cAMP accumulation by bones and isolated bone cells in culture. OAF was shown to stimulate accumulation of cAMP in mouse cranial bones at doses between 1 and 1000 ng/ml. Stimulation of bone resorption was observed in bones treated with the same doses of OAF. In order to investigate the cell types responsible for cAMP responses to OAF, we isolated bone cells and grew them in monolayer culture. The cells were isolated by a variety of techniques which separate bone cells into two types of parathyroid hormone (PTH)-responsive populations: (a) cells derived from the periosteal regions of the bone, which also respond to calcitonin with increases in cAMP; and (b) cells derived from the matrix, which do not respond to calcitonin. OAF caused elevation of cAMP levels in both the periosteum-derived cells and the matrix-derived cells. The magnitudes and time courses of OAF effects in these populations resembled the effects previously reported for PTH in the same populations. OAF stimulated adenyl cyclase in both types of cell populations, but did not produce significant changes in cAMP phosphodiesterase activity. OAF differed from PTH in that its effects on cAMP accumulation decreased sharply at supramaximal doses in both bone and isolated cells, especially in the matrix-derived populations. Bone resorption did not decrease as markedly as did cAMP accumulation at high doses of OAF, suggesting that cAMP accumulation and resorption could be dissociated under some conditions. These results indicate that OAF has effects on cAMP production in the same cell populations as PTH, and suggest that OAF could modify not only resorption but also formation of bone in vivo. OAF may exert its effects on bone by means of cAMP-dependent mechanisms, but more data will be necessary to establish this unequivocally. The observed differences between OAF and PTH may be of relevance in the mechanism and treatment of pathologic bone destruction in vivo.
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  • 62
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    Calcified tissue international 27 (1979), S. 199-204 
    ISSN: 1432-0827
    Keywords: Bone ; Parathyroid hormone ; Calcitonin ; Osteoporosis ; Paraplegia ; Hydroxyproline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In paraplegia, osteoporosis below the neurological lesion occurs early after the spinal cord affection. The serum levels of parathyroid hormone (PTH) and calcitonin (CT), using a radioimmunoassay for the measurement of immunoreactivity, were studied in 12 paraplegic patients for 9 months following onset. Serum Ca and P levels, urinary hydroxyproline excretion, and the kinetic metabolic clearance of45Ca have also been measured. P and immunoreactive (i) CT levels were found the highest at the beginning of the observation and progressively decreased with time. Ca and iPTH serum levels varied inversely with time, the highest level of Ca and the lowest level of iPTH being recorded at the third month following the paraplegia. Mean values of Ca, iPTH, and iCT were in the normal range throughout the study. P levels were increased during the first 3 months. Hydroxyprolinuria was also high and45Ca kinetics showed increased values of Vt, Vo+, and Vu. These parameters indicate a high degree of bone turnover. The results were consistent with the assumption that PTH is not responsible for the increased resorption of bone in paraplegia. Likewise, a deficiency of CT does not seem to be responsible for this bone resorption. These endocrine modifications could be secondary to an increase in the calcium flux from bone to blood and resulting from bone destruction as attested by the increase of urinary calcium and urinary hydroxyproline excretion.
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  • 63
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    Calcified tissue international 27 (1979), S. 233-237 
    ISSN: 1432-0827
    Keywords: Bone ; Vitamin D ; Acidosis ; Phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Vitamin D and phosphate deficiency were produced in rats in order (a) to evaluate the degree of bone mineral and matrix maturation using a bromoform/toluene density gradient technique; and (b) to compare the aforementioned bone maturational changes due to vitamin D and phosphate deprivation to those produced with superimposed severe acidosis. Rats were fed a diet deficient in vitamin D and phosphorus (0.2%) from 3 weeks through 7 weeks of age. To examine the additional contribution of dietary calcium, we gave one-half of the animals either a low (0.06%) or high (1.3%) calcium diet. Following the 4 weeks of vitamin D deficiency, one-half of each group was given 1.8% NH4Cl in the drinking water for 4 succeeding days to induce an acute, severe acidosis. The degree of bone maturation was quantitated via bromoformtoulene density gradient fractionation; total mineral and hydroxyproline (collagen) levels were quantitated as well. The vitamin D-deficient rats deprived of adequate dietary phosphate responded by conserving phosphorus, and as a consequence total bone phosphorus levels were maintained within that level for control rats. This conservation was independent of calcium intake but was extremely sensitive to acute acid loading, where a significant reduction in total bone phosphorus was noted. The bone maturational profile obtained from the vitamin D-phosphate deficient rats, however, revealed a significant accumulation of less mature or dense bone collagen and mineral with a corresponding decrease in the most mature or dense moieties. In contrast to the reduction of the total bone phosphorus content by acute acidosis, the skeletal collagen-mineral maturational profile was not significantly affected by the short-term systemic acidosis. The observed retardations in the bone collagen and mineral maturation of the vitamin D-deficient, phosphate-deprived state provide an additional observation which may well relate to the progressive osteopenia documented in states of chronic, mild acidosis.
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  • 64
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    Calcified tissue international 27 (1979), S. 275-279 
    ISSN: 1432-0827
    Keywords: Proline ; Cartilage ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Proline biosynthetic and degradative enzymes are unevenly distributed in differentiated mammalian tissues. Activities of the synthetic enzymes are relatively high in collagenous tissues, whereas activities of the degradative enzymes are high in noncollagenous tissues. In order to further characterize tissue-specific proline biosynthesis and degradation, we have determined proline enzyme activities during cartilage and bone formation induced by demineralized bone matrix. We can thus follow temporal changes in enzyme activity in a single tissue as different cell types develop. Ornithine aminotransferase and pyrroline-5-carboxylate reductase have peaks of activity which correlate with maximal type II collagen synthesis by chondrocytes. Both enzymes also are active during bone formation. In contrast, proline oxidase and pyrroline-5-carboxylate dehydrogenase are present at low levels and do not change as new cell types appear. Arginase activity peaks during the first 3 days and then rapidly decreases by the time cartilage and bone formation begin. These observations further substantiate the importance of proline biosynthesis in collagenous tissues. The close correlation between ornithine aminotransferase activity and type II collagen synthesis suggests that the pathway from ornithine to proline may be especially important during formation of type II collagen.
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    Calcified tissue international 27 (1979), S. 109-115 
    ISSN: 1432-0827
    Keywords: Bone ; Bending rigidity ; Disuse atrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The in vivo bending rigidity and bone mineral content of monkey ulnae and tibiae were measured. Bending rigidity in the anteroposterior plane was measured by an impedance probe technique. Forced vibrations of the bones were induced with an electromechanical shaker, and force and velocity at the driving point were determined. The responses over the range of 100–250 Hz were utilized to compute the bending rigidity. Bone mineral content in the cross section was determined by a photon absorption technique. Seventeen male monkeys (Macaca nemestrina) weighing 6–14 kg were evaluated. Repeatability of the rigidity measures was 4%. Bone mineral content was measured with a precision of 3.5%. Bending rigidity was correlated with the mineral content of the cross section,r=0.899. Two monkeys were evaluated during prolonged hypodynamic restraint. Restraint produced regional losses of bone most obviously in the proximal tibia. Local bone mineral content declines 17 to 24% and the average bending rigidity declines 12 to 22%. Changes in bones leading to a reduction in mineral content and stiffness are discussed.
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  • 66
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    Calcified tissue international 27 (1979), S. 13-18 
    ISSN: 1432-0827
    Keywords: Anticonvulsants ; Calcium ; Vitamin D ; Parathyroid hormone ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Parameters of mineral metabolism were examined in 6 patients with moderately severe anticonvulsant drug-induced osteomalacia. Compared to 15 matched controls, the patients exhibited significantly reduced serum calcium, inorganic phosphate, and 25-hydroxyvitamin D concentration, elevated serum alkaline phosphatase and immunoreactive parathyroid hormone (iPTH) concentration, reduced intestinal47Ca absorption, reduced urinary calcium and increased urinary hydroxyproline excretion, and reduced forearm bone mass. Intestinal absorption of vitamin D3 was normal. Following 4 months of treatment with vitamin D3 (4000 units/day), serum 25-OHD concentration was increased to 3 times mean normal values and all parameters except serum iPTH, urinary calcium excretion, and forearm bone mass were returned to levels not significantly different from normal. Serum iPTH concentration was reduced by 39% (P〈0.05); 24-h urinary calcium excretion rose by 98% (P〈0.001), and forearm bone mass increased by 5.6% (P〈0.05). It is concluded that moderate-dose vitamin D3 supplementation is effective in normalizing parameters of mineral metabolism in this disorder, despite evidence of resistance to the biologic effects of vitamin D.
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  • 67
    ISSN: 1432-0827
    Keywords: Calcium ; PTH ; 1,25(OH)2D ; Acid ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary We measured mineral and acid balances, serum iPTH, urinary cAMP/creatinine, and plasma concentrations of 25OHD and 1,25(OH)2D in 7 healthy adults during control conditions and during increased fixed acid production achieved either by the administration of NH4Cl (N=3) or by increased dietary protein intake (N=4). When acid production was increased, the subjects were in positive acid balance and negative Ca balance because of increased urinary Ca excretion. Serum iPTH fell slightly but urinary cAMP and the plasma levels of vitamin D metabolites did not change. We conclude that the accelerated skeletal and urinary losses of Ca that occur when fixed acid production is increased are not contributed to nor compensated for by the parathyroid-vitamin D endocrine systems.
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    Calcified tissue international 29 (1979), S. 101-105 
    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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    Calcified tissue international 29 (1979), S. 169-171 
    ISSN: 1432-0827
    Keywords: Glycosaminoglycans ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Compact bone tissue chondroitin sulphate, previously considered to be pure chondroitin-4-sulphate, was isolated from three adult human femoral diaphyses and digested with chondroitinase ABC. Assaying these digests by means of high performance liquid chromatography we could demonstrate that 12 to 14% of the disaccharide residues were 6-sulphated. The 4/6-ratios were also studied in chondroitin sulphate fractions of different molecular size. Slightly increasing amounts of 6-sulphated disaccharides were found with increasing size of the chondroitin sulphates.
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    Calcified tissue international 29 (1979), S. 7-13 
    ISSN: 1432-0827
    Keywords: Bone ; Culture ; Resorption ; Acidosis ; Alkalosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary We have examined the effects of H+, CO2, and HCO3 − concentrations during metabolic and respiratory acidosis and alkalosis on bone resorption in vitro. Rat fetal bones prelabeled with45CaCl2 were cultured at 2%, 5%, and 10% CO2 for up to 120 h, and the release of45Ca was measured in devitalized bones (non-cell-mediated45Ca release) and in live bones (cell-mediated45Ca release) cultured with or without PTH and 1,25(OH)2D3. Non-cell-mediated mineral loss was linearly related to H+ concentration but not to CO2 or HCO3 − concentration. This effect was observed on both labeled and stable calcium. Over a wide pH range (6.9–7.5) H+, CO2, or HCO3 − concentrations did not influence cell-mediated bone resorption in control or in PTH-and 1,25(OH)2D3-stimulated cultures. However, inhibition of cell-mediated bone resorption was observed at higher or lower pH irrespective of CO2 or HCO3 − concentrations. These observations demonstrate that the bone mineral mobilizing effect of acidosis in vitro is mainly due to the effect of changing H+ concentration on devitalized bone. Effects on cell-mediated bone resorption and hormonal response were observed only at extremes of pH. The effects of H+ were independent of changes in CO2 or HCO3 − concentration and could be responsible for the negative calcium balance and increased urinary loss observed in metabolic acidosis in vivo, but do not explain the reported differences in effects on calcium metabolism between respiratory and metabolic acidosis.
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  • 71
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    International archives of occupational and environmental health 44 (1979), S. 25-43 
    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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  • 72
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    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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  • 73
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    Journal of molecular medicine 57 (1979), S. 451-456 
    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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  • 74
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    Journal of cancer research and clinical oncology 95 (1979), S. 197-207 
    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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  • 75
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    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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  • 76
    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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  • 77
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    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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  • 78
    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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  • 79
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    Archives of microbiology 121 (1979), S. 9-15 
    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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  • 80
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    Archives of microbiology 123 (1979), S. 173-181 
    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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  • 81
    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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  • 82
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    Cell & tissue research 200 (1979), S. 15-27 
    ISSN: 1432-0878
    Keywords: Lymph vessels ; Testis ; Man ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of lymph vessels in the human testis was investigated using ink injection methods, and light and electron microscopy. Lymph capillaries occur in the septula testis but are absent in the intertubular tissue. They consist of endothelial cells provided with an incomplete basal lamina and anchoring filaments of the adjacent connective tissue. Frequently, the endothelial cells are separated by gaps measuring up to 2μm. The lymph capillaries of the septula testis are connected to lymph vessels in the rete testis and tunica albuginea. These vessels have occasional smooth muscle cells and valves. At the posterior margin of the testis, the network of lymph vessels merges into collecting ducts, which together with vessels derived from the rete testis are drained by the lymphatic system in the spermatic cord.
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  • 83
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    Cell & tissue research 200 (1979), S. 329-334 
    ISSN: 1432-0878
    Keywords: Median eminence ; Axon terminals ; Tanycytes ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present ultrastructural study proves the existence of nerve terminals closely apposed to the plasmalemmata of tanycytes in the rat median eminence. Several of these “axo-tanycytic” endings display remarkable accumulations of agranular endoplasmic reticulum in the form of pleomorphic vesicles which are closely apposed on either side of the plasma membrane of each cell compartment. Some of these vesicular profiles give the impression of structural continuity across both membrane systems. This phenomenon is discussed in the context of being a potential substratum for communication between both cell compartments.
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  • 84
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    Cell & tissue research 200 (1979), S. 337-344 
    ISSN: 1432-0878
    Keywords: Glomerulo-tubular feedback ; Tight junctions ; Macula densa ; Distal tubule ; Electron microscopy ; Freeze fracture ; Horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the present study the tight junctions at the macula densa were compared to those of the adjacent straight and convoluted segments of the distal tubule using freeze fracturing and thin sectioning techniques. Only insignificant differences were found in the number of strands and the apico-basal depth of the tight junctions in the three distal tubular segments of rat, dog and tree shrew. In experiments with horseradish peroxidase on mice and tree shrews, the tracer did not penetrate the apical junctions in any of the distal tubular segments. Our findings do not support the concept of considerably higher permeability of the tight junctions at the macula densa, as previously reported. Gap junctions were never observed in the distal nephron. The present results suggest that the glomerulo-tubular feedback is more likely to be mediated by transcellular resorption of solutes than by passive diffusion through a leaky paracellular shunt pathway.
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  • 85
    ISSN: 1432-0878
    Keywords: T-lymphocytes ; Blast cells ; Lymph node ; Electron microscopy ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Changes in the volumes and surfaces of subcellular compartments of unstimulated small lymphocytes and immunoblasts in mouse axillary lymph nodes have been established using stereological techniques. Blast transformation was induced in vivo with dinitrochlorobenzene (DNCB). Cell samples were obtained by random sampling regimes applied at light and electron microscopic levels. From electron micrographs the volume densities of euchromatin, heterochromatin, nucleoli, mitochondria, Golgi apparatus and rough endoplasmic reticulum were determined. Cell surface/volume ratios were also computed. By estimating mean nuclear volumes using light microscopy, it was possible to calculate absolute compartmental volumes and to evaluate the plasma membrane surface areas of average cells. Transformation in this model was characterized by a considerable cellular hypertrophy and a substantial increase in plasmalemma surface. Hypertrophy was the consequence of increases in the volumes of all measured intracellular compartments, notably euchromatin and “residual cytoplasm” (including ground cytoplasm and free ribosomes). These changes are discussed in the context of the altered metabolic status of cells.
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  • 86
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    Cell & tissue research 200 (1979), S. 435-442 
    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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  • 87
    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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    Cell & tissue research 198 (1979), S. 477-486 
    ISSN: 1432-0878
    Keywords: Embryonic heart ; Myogenesis ; Sarcomere ; Crustacea (Homarus americanus) ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cardiomyoblasts in the myocardium of embryonic lobsters at 3–4 weeks and 6 months of development were examined with the transmission electron microscope in order to describe the events in the formation of sarcomeres in a neurogenic cardiac system. Thick and thin myofilaments appear first in the cell periphery near the sarcolemma. They align in parallel in a sequential fashion to form consecutive sarcomeric units. Well-defined A and I bands appear before any semblance of a Z line is present. The initial sarcomere is anchored to the sarcolemma by the insertion of thin myofilaments into a region of electron dense material associated intimately with the sarcolemma. Myofibrils grow outward in several planes away from the electron-dense regions of membrane that serve as focal points for myofibril formation.
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    Cell & tissue research 198 (1979), S. 521-526 
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Electron microscopy ; L-DOPA ; Lysosomes ; Chinese quail, Excalfactoria chinensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intraperitoneally injected L-DOPA was found to stimulate strongly the lysosomal system of all of the cell types of the adenohypophysis. We suggest that this amine may play a role in the regulation of the secretory activity of the gland by mediating the lysosomal activity, this role being of variable importance according to the fluctuations in hormonal activity. Ultrastructural changes occur in some cell types following injection of L-DOPA. The question as to whether these changes are induced directly by L-DOPA or via the monoaminergic system of the hypothalamus and its hypophysiotropic hormones is discussed.
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    Cell & tissue research 199 (1979), S. 509-517 
    ISSN: 1432-0878
    Keywords: Olfactory bulb ; Giant cells ; Neurosecretion ; Electron microscopy ; Labyrinth fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The giant cells in the olfactory bulb of labyrinth fish, most likely belonging to the nervus terminalis, show ultrastructural features of active synthesis of secretory material. Dense core vesicles (70–100 nm in diameter), found in the perikaryon as well as in the axon, are the possible storage sites of the secretory substance. Its chemical nature is unknown. In some of these vesicles acid phosphatase is demonstrable. Large membrane-bound bodies (up to 2000 nm in diameter), either containing an electron dense matrix or debris of cytoplasmic organelles, are also acid phosphatase-positive, suggesting their lysosomal nature. Some other ultrastructural characteristics of these cells are also described.
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    Cell & tissue research 201 (1979), S. 159-163 
    ISSN: 1432-0878
    Keywords: Insulin secretion ; Acid-base changes ; Electron microscopy ; Pancreas perfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural changes in pancreatic β cells were studied following glucose-induced insulin secretion in vitro, at two different extracellular pH (7.4 and 7.8). The pancreata perfused at pH 7.4 exhibited a biphasic insulin response to glucose challenge together with signs of increased emiocytotic activity and numerous microtubules in the β cells. Conversely, the pancreata perfused at pH 7.8 showed a significant decrease in insulin secretion, and their β cells revealed scarce emiocytotic images and a marked increase of intracellular granulolysis. These results represent the ultrastructural correlate of the reduced insulin secretion produced by metabolic alkalosis in the perfused rat pancreas.
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  • 92
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Steroid release ; Rabbit ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the rabbit adrenal cortex was investigated. The parenchymal cells display the ultrastructural features of steroid-producing cells, and also contain numerous electron-dense bodies frequently located near intercellular canaliculi, which open into the subendothelial space. Short-term ACTH-administration induced a noticeable decrease in the volume of the lipid compartment in the cells of all three cortical zones and a significant increase in the volume of dense bodies in the cells of zona fasciculata and zona reticularis. The hypothesis that these dense bodies are secretory granules is discussed in the light of biochemical evidence showing that ACTH increases the concentration of both corticosterone and cortisol in the decapsulated-enucleated adrenal homogenate and does not affect the activity of two lysosome-marker enzymes (i.e., acid phosphatase and β-glucuronidase).
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  • 93
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    Cell & tissue research 199 (1979), S. 171-175 
    ISSN: 1432-0878
    Keywords: Crustaceans ; Neuromuscular synapse ; Multiterminal innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of nerve terminals from a single excitatory motor axon has been followed along a fiber from the proximal accessory flexor muscle of the lobster by thin serial sectioning at periodic intervals. The excitatory motor axon provides small axonal branches (diameter 5–12 μm) of varying lengths that travel along the surface of the muscle fiber. Each of these branches gives rise to discrete synaptic terminals which are not uniformly distributed. Individual terminals vary in length from 10–60 μm and the majority possess neuromuscular synapses. The greatest distance between synapses is slightly over 1 mm which is well within the length constant (2.6 mm) of this muscle fiber. Thus the spatial distribution of synapses is such as to ensure adequate depolarization along the entire length of the muscle fiber.
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  • 94
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    Cell & tissue research 199 (1979), S. 281-288 
    ISSN: 1432-0878
    Keywords: Annular microtubules ; Nodes of Ranvier ; Nerve ; Axon ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using a special albumin technique, nodes of Ranvier have been examined within frog skeletal muscle, sciatic nerve and rat and frog cerebrum. Initial segments have been examined in cerebrum of frog and rat. Microtubules usually run longitudinally through these regions, but within the bare area of the intramuscular node of Ranvier, annular or helical bundles of microtubules run in a marginal band at right angles to the more centrally placed longitudinal microtubules. These nodal bare areas show a pronounced convexity and it is suggested that the annular microtubules serve to maintain this convexity during muscle contraction.
    Type of Medium: Electronic Resource
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  • 95
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    Electronic Resource
    Springer
    Cell & tissue research 201 (1979), S. 37-44 
    ISSN: 1432-0878
    Keywords: Brush cell ; Receptor ; Lateral microvilli ; Gallbladder ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The brush cells of the gallbladder epithelium of the mouse have microvilli not only at their luminal border but also on their lateral surface, from the level of the nucleus to the junctional complex. The lateral microvilli radiate from the brush cell in all directions, contain a core of filaments, and penetrate up to 3 μm into the adjacent cells. The microvilli in these locations display small desmosomes at their base.
    Type of Medium: Electronic Resource
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  • 96
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    Springer
    Cell & tissue research 201 (1979), S. 451-458 
    ISSN: 1432-0878
    Keywords: Epididymis ; Freeze-fracture ; Electron microscopy ; Male reproduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epithelium of the monkey epididymis was studied by means of freeze-fracture techniques and conventional electron microscopy. For the study of transepithelial permeability lanthanum hydroxide was used as an intercellular tracer. The epididymal epithelium consists mainly of tall columnar cells. The long stereocilia at the apical surface, similarly to microvilli, exhibit after freeze-fracture, two distinct faces: the E face, concave and with fewer membrane-associated particles, and the complementary convex P face. In the lumen unusual groups of smooth-surfaced vacuoles are present. A tight junctional network, which shows some permeability to the lanthanum tracer, is located at the apical end of the cells. Supranuclear cross-fractures clearly show the well developed Golgi cisternae and numerous vacuole profiles. The highly infolded, centrally located nucleus exhibits, after freeze-fracture, an even distribution of nuclear pores. In the perinuclear region the rough endoplasmic reticulum, which also presents pores, displays a sheet-like organization. The basal cytoplasm is filled by numerous globular profiles of membrane-bounded granules. Freeze-cleave exposes large cytoplasmic areas where the types and amount of organelles indicate an intense metabolic activity.
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  • 97
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 201 (1979), S. 467-477 
    ISSN: 1432-0878
    Keywords: Anterior pituitary ; Hormone synthesis ; Morphometry ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to compare the functional state of the anterior pituitary of spontaneously hypertensive rats (SHR) with that of normotensive Wistar Kyoto rats (WKR), the anterior pituitary was examined by morphometry and autoradiography at the level of electron microscopy. The relative number and the relative volume of thyrotrophs in the anterior pituitary were significantly greater in SHR compared with age-matched WKR at 0, 7, 30–33 days, and 10 months of age, while the relative number of somatotrophs in SHR was significantly smaller at 1 and 10 months of age. Electron microscope autoradiographic analysis of uptake of 3H-lysine by thyrotrophs of both strains at the age of approximately one month showed that 3H-lysine was incorporated into protein and transported finally to secretory granules which migrated to near the cell membrane to be discharged. Silver grains were significantly more numerous over the thyrotrophs of SHR than over those of WKR at 30 min, 1 h, and 4h after the injection of 3H-lysine. The present study has ascertained morphologically that a congenital hypersynthesis of TSH by the anterior pituitary occurs in SHR.
    Type of Medium: Electronic Resource
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  • 98
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    Electronic Resource
    Springer
    Cell & tissue research 202 (1979), S. 125-132 
    ISSN: 1432-0878
    Keywords: Macrophage ; Osteoclast ; Bone resorption ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural observations on macrophage-mediated resorption of calcified tissue of killed fetal long bones are described and correlated with increased 45Ca release into the medium. Macrophages disrupt calcified tissue extracellularly and appear to engulf large fragments of mineralized matrix. Ruffled borders, which are common features of osteoclasts at sites of resorption of bone, do not develop in macrophages. However, clear zones are seen in macrophages as well as osteoclasts. These findings provide additional evidence for non-osteoclast-mediated resorption of calcified tissue.
    Type of Medium: Electronic Resource
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  • 99
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 201 (1979), S. 101-127 
    ISSN: 1432-0878
    Keywords: T-lymphocytes ; Cell activation ; Stereology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Stereological data of phytohaemagglutinin (PHA)-activated human T-lymphocytes were recorded at intervals (12 to 72 h) together with biochemical (isotope-uptake, lymphotoxin-release) and morphological measurements. About 98 % of the cells were activated 12 h after PHA-stimulation. The activation phase lasted less than 48 h, i.e., cells entering the activation phase within 12 h were at their activation maximum by 48 h. The activated cell increased in size. The nuclear/cytoplasmic-ratio decreased. Most of the cytoplasmic organelles developed in phase with the increase of cytoplasmic volume. After 48 h, mitotic figures were frequently seen. Due to the increasing number of secondary, activated daughter cells, parameters of most cytoplasmic components declined between 48 and 72 h. Structural changes in the nucleus preceded the 3H-leucine uptake, which had not reached its maximum after 72 h of incubation. The 3H-leucine uptake started as early as 12 h after culture initiation, and its increase was proportional to the increasing polyribosome density. No maximum uptake was reached up to 72 h, but the development of structural components related to this uptake was at its maximum at the end of the activation phase (48 h). The formation of bound ribosomes occurred subsequent to the enlargement of the surface of the rough endoplasmic reticulum. Initial polysome formation occurred at the expense of existing free ribosomes.
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 201 (1979), S. 459-466 
    ISSN: 1432-0878
    Keywords: Electron microscopy ; Collagen ; Cuticle ; Lumbricus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A method has been developed to isolate and purify cuticular fibrils of Lumbricus. Polarizing microscopy confirms the collagenous nature of the isolated fibrils. Study in the electron microscope of isolated fibrils, negatively or positively stained, shows that they are cylindrical, unbranching and without periodic structure. Enzymatic treatment of cuticles with alpha-amylase and trypsin results in a more or less complete dissociation of the fibrils which appear clearly to be made up of helically wound bundles of filaments (30–40 Å). The structure of the cuticular fibrils is discussed in relation to biochemical and biophysical data and compared to the ultrastructural organization of other periodically cross-banded fibrils.
    Type of Medium: Electronic Resource
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