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  • 1975-1979  (1,448)
  • 1890-1899
  • Biochemistry and Biotechnology  (885)
  • Ultrastructure  (563)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 185 (1979), S. 333-346 
    ISSN: 1432-041X
    Keywords: Chick embryo ; Limb bud ; Ultrastructure ; Cell death
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructural changes in the wing bud afterapical ectodermal ridge (A.E.R.) removal was studied to re-examine the issue of distal mesenchymal cell death. The A.E.R. of the right wing bud was removed microsurgically from chick embryos of stages 18 to 22 (HH 1951). The wing buds were examined at three hour intervals up to twelve hours after the operation with light, transmission and scanning electron microscopy. The main findings were: (1) Immediate and temporary shrinkage of the mesenchymal extracellular space 100 to 150 μm and chromatin condensation in the cells 50 to 75 μm from the wound. (2) Death of ectodermal and mesenchymal cells in the immediate vicinity of the wound. (3) Formation of a single squamous-like layer of mesenchymal cells to cover the wound. (4) Occasional evidence of cell death in the distal mesenchyme at later times after the operation. The pattern of cell death observed suggests only a traumatic etiology, and gives little evidence for the postulated developmental significance of cell death following A.E.R. removal.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Development genes and evolution 186 (1979), S. 65-70 
    ISSN: 1432-041X
    Keywords: Sea urchin ; Embryo ; Collagen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Collagen fibrils with a main period banding of 610 Å and 220 Å in width were observed in the blastocoel of 72-h embryos of the sea urchin,Strongylocentrotus purpuratus. Non-striated fibrils of 50 Å diameter were also observed. The collagen is seen in highest concentration in the vicinity of mesenchyme cells which are richly endowed with endoplasmic reticulum and secretory vesicles. A role for collagen in cell attachment, orientation and spicule formation is discussed.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 155 (1979), S. 95-105 
    ISSN: 1432-0568
    Keywords: Metanephros ; Chicken embryo ; Ultrastructure ; Parathyroid hormone ; Cyclic AMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A comparative electron microscopical study was conducted on the metanephros from chick embryos differentiated either in shell-less culture or in ovo. Developmental characteristics were very similar in both cases. Up to stage 37 (Hamburger-Hamilton) the metanephros contained large numbers of immature nephrons; their renal corpuscles were crescent-shaped and consisted of an outer layer of flat cells and an inner one of cuboidal cells. In more advanced corpuscles also found at this stage the inner layer had formed numerous rudimentary pedicels and the tunica media of the glomerular arteriole contained juxta-glomerular cells with numerous, small, electron dense granules. In the metanephros from embryos at stage 38 or older, large numbers of nephrons had completed their differentiation; their rounded renal corpuscles had fully differentiated podocytes with thin interdigitating pedicels and the proximal convoluted tubules had numerous apical microvilli, vesicles, vacuoles and tubular invaginations indicating an active process of resorption. These results appear to indicate that both in culture and in ovo-developed embryos, the metanephri start to function around stage 38. In the case of normal embryos this conclusion agrees with previous physiological and biochemical determinations. The injection of 20 USP parathyroid hormone into 16-day old chick embryos produced an increase in the concentration of cyclic AMP in the metanephros. This favours the idea that the regulation of kidney function by the hormone begins during the embryonic period.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 156 (1979), S. 73-88 
    ISSN: 1432-0568
    Keywords: Closure ; Development ; Mammalina embryo ; Neural tube ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fusion of the neural walls in the cephalic part of mouse embryos varying in age from 9 to 20 somites was examined with the electron microscope. In the rhombencephalic region the rim of the neural wall was formed from outside inward by ectodermal surface cells, a row of flattened cells without surface projections and neuroepithelial cells. At the junction of the surface ectoderm and the flat cells were seen large projections containing a cytoplasmic matrix without organelles and previously referred to as “ruffles”. The initial contact between the walls was made by the large cytoplasmic arms and numerous finger-like projections interdigitating with similar projections from the opposite wall. The projections originated from the surface ectoderm and possibly neural crest cells. During further fusion the surface ectoderm cells formed dense membrane specializations, thus establishing a firm contact. The initial contact in the mesencephalon was formed by extensions from the surface ectoderm and was followed by the formation of specialized membrane junctions, as seen between the surface ectoderm in the rhombencephalon. The neuroepithelial cells facing the gap between the neural walls with their apical ends made contact with the cells from the opposing wall by numerous finger-like projections but membrane specializations failed to develop. The closing mechanism in the prosencephalon and anterior neuropore regions differed from the previous areas in that the initial contact was established by the neuroepithelial cells. Only after this contact had been formed did the surface ectoderm cells close the gap. In contrast with the other areas many phagocytosed particles were seen in the prosencephalon and in the region of the anterior neuropore. Many particles from degenerated cells were found inside healthy surrounding cells. Some of these particles contained nuclear material and cytoplasmic organelles.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 155 (1979), S. 333-345 
    ISSN: 1432-0568
    Keywords: Lipofuscin ; Cerebellar cortex ; Ultrastructure ; Senescent rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of autofluorescent, PAS-positive lipofuscin in Purkinje, granule, Golgi epithelial, basket and stellate, microglial and perivascular cells in the cerebellar cortex of senescent rats is described. The membrane-bounded pigment is composed of three elements: 1) electron-lucent homogeneous droplets, 2) a granular matrix and 3) intensely osmiophilic patches. The proportions of these three components vary between cell types and one can grossly differentiate a neuronal and a glial lipofuscin. The lipofuscin granules of stellate and perivscular cells are different from lipofuscin of other cerebellar neurons and glia. It can be concluded from these morphological observations that each cerebellar cell type has its distinct lipofuscin.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 156 (1979), S. 255-267 
    ISSN: 1432-0568
    Keywords: Adenohypophyseal rudiment ; Self-differentiation ; Ultrastructure ; Quail
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Isolated epithelial rudiments of 3–4 days quail embryo adenohypophysis were cultivated in vitro. Differentiation of glandular cells occured when culture conditions allowed the formation of explants characterized by the presence of a fibroblastic sheet and of an epithelial roof surrounding a central cavity. Differentiation did not occur when culture conditions did not allow the fibroblastic sheet to be established or resulted in the absence of a cavity. The importance of the explant structure in differentiation is also indicated by the location of glandular cells. In vitro they differentiate near the cavity derived from Rathke's pouch lumen while in situ they first appear at the periphery of the rudiment, near the basement membrane. The results of this study show that the adenohypophyseal primordium can differentiate without any mesenchymal influence. The observed differentiation seems to be correlated with fibroblast-secreted material, and this hypo-thesis is discussed.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 47 (1979), S. 139-143 
    ISSN: 1432-0533
    Keywords: Perineurium ; Permeability ; Peripheral nerve ; Rat ; Ultrastructure ; Autoradiography ; Albumin ; Peroxidase ; Protein deprivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The permeability properties of the perineurium in sciatic nerves of 12-week-old rats were studied. The penetration of125I-labeled albumin and horseradish peroxidase into the perineurium was investigated electronmicroscopically 10, 30, and 120 min after the local extraneural application of the tracers. The autoradiographic study included age-matched protein-deprived rats. It was concluded that the perineurium acted as a diffusion barrier but also permitted a slow passage of the macromolecules into the endoneurium. The result indicates that this penetration to some extent is due to vesicular transport across the perineurial cells. The significance of these barrier and transport properties of the perineurium is discussed. No obvious differences in perineurial permeability between normal and protein-deprived rats were obtained.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 48 (1979), S. 67-72 
    ISSN: 1432-0533
    Keywords: Pituitary adenoma ; Ultrastructure ; Classitication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of pituitary adenoma secreting more than two hormones is presented. Morphological findings of this tumor have been correlated with biological behavior and with hormonal activity.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 46 (1979), S. 215-220 
    ISSN: 1432-0533
    Keywords: Melanosis of the dentate nucleus ; Glial melanin ; Ultrastructure ; Intrared spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The pigment present in melanosis cerebelli where it is deposited in the dentate nucleus and within the cerebellar granular layer is similar to that of S. nigra as judged from the typical infrared absorption bands near wave numbers 3.450 cm−1 and 1.650 cm−1, respectively. According to electron microscopic findings, this type of melanin arises within the astrocytes of the dentate nucleus. The astrocytic melanosomes exhibit a relatively monotonous substructure reaching diameters of 30 μ and more, and they differ in this respect from the triadic neuronal melanosomes of S. nigra that are strongly reminiscent of lipofuscin granules. These differences may be due to additional components of melanosomes, apparently specific of a particular cell type, and they are in turn accounted for by the dissimilar cellular metabolic make-up of nigral cells and astrocytes, respectively. This does not dismiss the possibility, however, that the melanin pigments of either type of melanosomes are the same or closely related to each other as far as their basic chemical composition is concerned. The cause of the melanosis of the dentate nucleus is not known. Possibly involutional tissue changes governed by endocrine factors among others may play an important part.
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  • 10
    ISSN: 1432-0533
    Keywords: Muscular dystrophy ; Becker-type ; Benign X-linked ; Histopathology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscle biopsies of two patients originally reported in the Göttingen family by Becker (1962) that formed the basis of separating a benign X-linked muscular dystrophy from the rapidly progressive Duchenne-type X-linked muscular dystrophy, revealed mild pathological changes in the younger patient and more advanced in the older one, consisting of increased spectra of fiber diameters, endomysial fibrosis, angulated fibers, pyknotic nuclear clumps and small groups of atrophic fibers. Essentially, both biopsies showed the same changes, but of different severity, possibly due to the differences in age and muscle biopsy sites. These changes were regarded “myopathic”, but a neurogenic component was suggested. Our observations accord well with those of a larger series (Bradley et al., 1978) where both electromyography and histopathology revealed a mixed “myopathic-neurogenic pattern” in patients with Becker-type dystrophy. Differential diagnostic aspects encompass Duchenne's muscular dystrophy, the other hereditary dystrophies and X-linked proximal spinal muscular atrophies. The precise nature of Becker-type muscular dystrophy requires morphological data on peripheral nerves, spinal roots and spinal cord anterior horn cells as well as sequential biopsy analysis to substantiate the primary site of pathology. However, on the basis of available data, it seems reasonable to suggest that the early changes of degeneration/regeneration which are accompanied by a markedly elevated CPK eventuate in the histopathologic and electromyographic patterns illustrated in these two patients with Beckertype dystrophy.
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  • 11
    ISSN: 1432-0533
    Keywords: Visna ; Slow viral infection ; CSF ; Ultrastructure ; Myelin fractions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscopic examination was done on 8 samples of cerebrospinal fluid (CSF) from Icelandic sheep infected by the intracerebral route with visna virus. The specimens were collected 1 month, 2 months, and 4 years after infection. A differential cell count done on low-power electron micrographs showed that the cellular exudate was composed of mononuclear cells mainly macrophages and lymphocytes with a few plasma cells. Macrophages were with one exception more numerous than lymphocytes and an increased proportion of macrophages showed evidence of phagocytosis with time after infection. Reactive lymphocytes were in general more numerous than small lymphocytes. Various stages in the maturation of plasma cells were observed. The cellular composition in the CSF is compatible with the view that visna is an immunopathological process. Myelin figures and fragments of myelinated axons were observed in two specimens indicating an active myelin-breakdown. The possibility that escape of myelin into the CSF may lead to sensitization to myelin antigens and perpetuation of this chronic neurologic affection is discussed. Visna virions could not be demonstrated.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 45 (1979), S. 17-25 
    ISSN: 1432-0533
    Keywords: Brindled mutant mouse ; Male hemizygotes ; Neuronal degeneration ; Ultrastructure ; Giant mitochondria ; Copper deficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The brindled mouse (Mobr) is a neurological mutant mouse with clinical and biochemical features closely similar to Kinky hair syndrome (KHS) in humans. Neuronal degeneration in the cerebral cortex and thalamic nuclei was the constant neuropathological lesions in the CNS of the male hemizygotes of this mutant (Yajima and Suzuki, 1978). Ultrastructurally, many cortical neurons contained enlarged mitochondria with prominent tubular or vesicular cristae, which were similar to those described in the Purkinje cells in the human KHS (Ghatak et al., 1972) and in the rat brain with copper deficiency (Prohaska and Wells, 1975). Such mitochondria were observed not only in the degenerating neurons but even in the otherwise normal-appearing cortical neurons, suggesting that the mitochondrial damage possibly related to the deficient activities of the copper containing enzymes (cytochrome oxidase, etc.) preceded the neuronal degeneration. Many mitochondria in the severely degenerated neurons contained numerous electron dense spicules of possible calcium. Although rare, similar morphological alteration of neuronal mitochondria was also noted in the female heterozygotes, indicating the presence of possible subclinical defect in copper transport in the heterozygotes as well.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 45 (1979), S. 111-115 
    ISSN: 1432-0533
    Keywords: Brain tumor ; Rhabdomyosarcoma ; Mesenchymal cell ; Myotube ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of primary cerebral rhabdomyosarcoma in a 51-year-old female is reported. The histogenesis of this tumor is discussed. The clinicopathological features of 10 previously reported similar tumors of the CNS are briefly reviewed. Histologically the tumor was polymorphic, but composed of poorly differentiated cells interpreted as rhabdomyoblasts without definite cross-striation. Electron microscopy established that the poorly differentiated cells were of rhabdomyosarcomatous nature, compatible with presumptive myoblasts and analogous to developing fetal muscle.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 46 (1979), S. 11-15 
    ISSN: 1432-0533
    Keywords: Meningioma ; Cell culture ; Ultrastructure ; Cell junctions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural alterations in human meningioma cells grown in vitro are reported. In early passages the cells retain some of the characteristic features of the original tumors. These include interdigitations associated with intercellular junctional devices (e.g., desmosomes, gap junctions). However, with repeated subculture these features tend to be less frequent. Typical whorl formations are observed only in primary cultures. The nunber of cytoplasmic filaments, lipid inclusions and other dense bodies increases with time in culture. Cytoplasmic invaginations into nuclei and the appearance of very large cells become more frequent in repeatedly transferred cultures.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 47 (1979), S. 85-92 
    ISSN: 1432-0533
    Keywords: Isoniazid ; Neuropathy ; Intoxication ; Dying back ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Large single doses of isoniazid by mouth (1–2 g/kg) have been shown to produce in rats Wallerian degeneration visible with the light microscope from the third day onwards. By contrast, changes in axons are seen from 24 h onwards by electron microscopy. The earliest ultrastructural changes are associated with vacuoles appearing between axon and Schwann cells. These are large and focal, and often compress the axon. The adjacent axon may show changes in smooth ER, and in microtubular arrangement. Alterations in smooth membranes and in mitochondria are visible in Schwann cell cytoplasm, not necessarily related to the vacuole formation and axonal features. It is suggested that INH neuropathy is essentially a multifocal axonal lesion.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 47 (1979), S. 75-79 
    ISSN: 1432-0533
    Keywords: Neurotoxicity ; Cyanate ; Demyelination ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of sodium cyanate (NaNCO) on the nervous system of Maccaca nemestrina were studied at 2, 4, and 6 months of administration of the drug. The two groups injected with daily doses of 35 and 25 mg/kg/day of Na-cyanate developed a predominantly demyelinating lesion in the pyramidal tracts of the spinal cord. No neuronal changes were observed in the motor cortex, basal ganglia, midbrain, medulla or anterior horn cells of the spinal cord. There was no evidence of peripheral neuropathy. A comparison between the cyanate induced neuropathy in the rat and in the primate was drawn. Ultrastructurally, both species developed a demyelinating process of central or peripheral myelin characterized by vacuolation of the myelin sheath, removal of myelin debris by macrophages and re-myelination. There was little evidence of axoplasmic damage except for an occasional distended fiber containing abundant dense bodies and whorls of neurofilaments. Oligodendrocytes and Schwann cells were electron microscopically intact and participated actively in remyelination. Maccacas maintained at 15 mg/day and sham animals remained normal clinically and anatomically. The predominantly myelinotoxic effect of cyanate is similar to that produced by other myelinotoxic agents and is attributed to a selective modification of myelin proteins by carbamylation.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 48 (1979), S. 211-214 
    ISSN: 1432-0533
    Keywords: Medullomyoblastoma ; Desmoplastic medulloblastoma ; Teratoid ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of cerebellar medullomyoblastoma in a young boy was investigated by electron microscopy. The neuroectodermal component shows the characteristics of a desmoplastic medulloblastoma. The mesodermal component consists of more or less differentiated cross-striated muscle cells. Undifferentiated muscle cells are very similar to proliferated endothelial cells of blood vessels within the muscular component, so that an origin of this component from pluripotential endothelial cells of the vessel wall is suggested. This tumor is considered a malignant teratoid because of the derivation from two blastodermic layers and because of the midline localization in children suggesting a malformative origin.
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  • 18
    ISSN: 1432-0533
    Keywords: Melanin ; Melanosomes ; Ultrastructure ; Infrared spectrophotometry ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Melanosomes and isolated melanosomal fragments (melanin particles) originating from gangliocytes (substantia nigra), astroglia (melanosis cerebelli), and melanocytes (melanotic meningeoma; metastases of melanoblastoma; melanosis thalami of the goat) were compared with synthetic melanins prepared from dopamine and serotonin, respectively. Samples were examined by electron microscopy, X-ray diffraction analysis according to Debye-Scherrer and by infrared spectrophotometry, and the results were evaluated with regard to characteristic features as they may relate to specific cell types or chemical structures. On electron microscopy all three types of melanosomes could be differentiated unequivocally as could the two synthetic melanins. Thus, there were similarities between synthetic melanin from dopamine and the gliogenic melanins of the cerebellum; the synthetic melanin from serotonin resembled melanin of melanocytes. X-ray diffraction analysis yielded 2-4 Debye diffraction rings with all human and synthetic samples, suggesting short range orders between 3.8 to 5 Å the sample obtained from a goat with thalamic melanosis showed a specific reflex pattern. While diffraction patterns of some melanins were partially identical, in particular that of melanin from dopamine and melanin of substantia nigra and dentate nucleus, respectively, they were different for the various melanocytic melanins. Further investigations are required to determine whether these differences are due to disparities in basic chemical structures or conformations or else, to particular compositional features of the various types of melanocytes as they arise from benign or malignant tumors or a specific species. Infrared spectrophotometry at higher wave numbers revealed the well known patterns of melanins, which are not, however, very suitable, for their further differentiation. At lower wave numbers (‘fingerprinting’) melanin of substantia nigra and the glial melanin in melanosis cerebelli yielded additional absorption bands of identical configuration. In contrast to melanin from dopamine, melanin from serotonin exhibited a closely similar absorption pattern in this spectral range, suggesting that the neuroectodermal melanins may contain a component possibly arising from serotonin.
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 45 (1979), S. 159-160 
    ISSN: 1432-0533
    Keywords: Tight junction ; Choroid plexus papilloma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four cases of choroid plexus papilloma (CPP) obtained at the time of surgical excision were examined by electron microscopy and compared with normal choroid plexus (CP) of mouse and chick. In apical tight junctions fusion of the two outer leaflets of the adjacent cytoplasmic membrane was verified as in CP. This fact suggests that there is a blood-CSF barrier not only in CP but also in CPP.
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 48 (1979), S. 27-30 
    ISSN: 1432-0533
    Keywords: Progressive supranuclear palsy ; Neurofibrillary tangles ; Ultrastructure ; Straight tubule ; Twisted tubule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of neurofibrillary tangles in the hippocampal gyrus, substantia nigra, pontine nuclei and locus coeruleus of the brain was postmortem studied in a case of progressive supranuclear palsy. Straight tubules and twisted tubules were observed in both the cortical and subcortical neurofibrillary tangles. Most tubules appeared separately in each neuron but a few straight tubules were mixed with the twisted tubules in the cortical tangles. The implication and possible significance of this findings are discussed.
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  • 21
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    Acta neuropathologica 48 (1979), S. 189-197 
    ISSN: 1432-0533
    Keywords: Hamster brain cells ; Polyoma virus ; Tumorigenicity ; Ultrastructure ; Specific nervous proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The morphological characteristics of three clones of hamster brain cells transformed in vitro by polyoma virus and of the tumors obtained after subcutaneous grafting of these cells in syngenic animals are reported. These clones appeared to be glial in nature by light and electron microscopy. The initial tumors induced by the three clones presented astrocytic features both by electron microscopy and immunohistochemistry. Analysis of the subsequent in vivo passages showed a decrease in cell differentiation, which was accompanied by a decrease in the latency period; after 2 years of serial transplantation, the tumors seemed poorly differentiated gliomas. A control cell line of hamster cerebellar cells evolved similarly.
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  • 22
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    Archives of microbiology 122 (1979), S. 17-27 
    ISSN: 1432-072X
    Keywords: Gliding bacteria ; CO2-requiring ; Periodontal disease ; Gram-negative ; Ultrastructure ; Capnocytophaga
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gram-negative, anaerobic gliding bacteria were isolated from normal supragingival plaque and from periodontal lesions. Isolates could be divided into two size classes: small 2.4–4.2 μm×0.38–0.5 μm and large 4.8–5.8 μm×0.42–0.6 μm cells. The outer membrane was either loose-fitting and wavy, or taut, and of variable thickness. An electron-dense fuzz was discernible on several of the isolates. The periplasmic region was of variable electron-density. The genus Capnocytophaga has been proposed for these organisms based on morphological and cultural characteristics.
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  • 23
    Electronic Resource
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    Archives of microbiology 121 (1979), S. 53-59 
    ISSN: 1432-072X
    Keywords: Saccharomyces ; Kluyveromyces ; Ultrastructure ; Ascospore wall ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three types of structure of the ascospore wall were found among the haploid Saccharomyces species examined: a warty wall (S. rouxii), a smooth wall with a single electron-light inner layer (S. bailii) and a smooth wall with a double light inner layer (S. montanus, S. florentinus). The latter type also occurred in Kluyveromyces thermotolerans and K. waltii. In K. fragilis spores the wall had a single light inner layer. The taxonomic implications of these findings were discussed.
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  • 24
    ISSN: 1432-072X
    Keywords: Methanogenium cariaci ; Methanogenium marisnigri ; Marine methanogenic bacteria ; Ultrastructure ; TaxonomyMethanogenium gen. nov.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A new genus of marine methanogenic bacteria and two species within this genus are described.Methanogenium is the proposed genus andMethanogenium cariaci the type species. Cells of the type species are Gram-negative, peritrichously flagellated, irregular cocci with a periodic wall surface pattern. Colonies formed by these bacteria are yellow, circular and umbonate with entire edges. The DNA base composition is 52 mol% guanine plus cytosine. Formate or hydrogen and carbon dioxide serve as substrates for growth. Cells ofMethanogenium marisnigri are of similar shape but smaller diameter thanM. cariaci. The colonies ofM. marisnigri are convex, and the DNA base composition is 61 mol % G+C. Formate or hydrogen and carbon dioxide are growth substrates. Sodium chloride is required for growth of both methanogens.
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  • 25
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    Experimental brain research 35 (1979), S. 249-267 
    ISSN: 1432-1106
    Keywords: Abducens nucleus (cat) ; Peroxidase ; Neurones ; Synapses ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light and electron microscope studies of the abducens nucleus in the cat have disclosed two populations of neurones: large neurones 25 to 75 μm in diameter and small neurones 10 to 25 μm in diameter. Characteristic of the large neurones are a highly developed granular endoplasmic reticulum and a large number of axo-somatic synapses. The small neurones have a poorly developed granular endoplasmic reticulum and comparative by few axo-somatic synapses. Injection of horseradish peroxidase (HRP) into the ipsilateral lateral rectus muscle has been used to identify abducens motoneurones which represent 65% of the total number of cells in the abducens nucleus and form part of the large cell population. The remaining unlabelled large neurones (30% of the large cell population) probably represent motoneurones of the retractor bulbi muscles, abducens motoneurones which have failed to transport the HRP, and possibly internuclear neurones. The small neurones (5% of the total cell population) were never labelled by HRP. Axo-somatic and axo-dendritic synapses are numerous. Many of the synaptic terminals form contacts with two or more different postsynaptic elements. Axo-axonic synapses and synapses on the initial segments of large neurones are also present. Nodal synapses and branching of myelinated axons are common findings. Finally, extended areas of close apposition between dendritic membranes are frequently observed.
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  • 26
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Ultrastructure ; Second axotomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The left hypoglossal nerve of adult male albino rats was prevented from regenerating to the tongue after a distal axotomy by implanting the proximal stump into normally innervated left sternomastoid muscle. Eighty-four days after implantation, the hypoglossal nerve was transected again and its regeneration to the tongue unimpeded. From 8 to 70 days after this second axotomy the left hypoglossal nuclei were processed for quantitative ultrastructural analysis. The first aim of this study was to compare regeneration success in the hypoglossal nucleus after second axotomy with that accompanying outgrowth of the hypoglossal nerve into denervated sternomastoid muscle. During quantitative analysis a second aim developed, of elucidating bouton/glial relationships. The second axotomy induced loss and return of subsurface cisterns, dispersal and reassembly of Nissl substance, increase and decrease of microglial numbers, slight further loss and partial return of boutons with clear spherical vesicles and symmetrical synapses, slight increase and decrease of boutons with clear flat vesicles and symmetrical synapses, regrowth of retracted dendrites and restoration of their synapses, and gradual diminution of numbers of electron-dense neurones and dendrites. Astrocytes remained hypertrophied throughout. When compared with events in the hypoglossal nucleus accompanying innervation of denervated sternomastoid muscle by the hypoglossal nerve, the results suggest (1) that regeneration of the hypoglossal nerve to its own tongue muscle instead of to a foreign muscle caused no acceleration of recovery in the hypoglossal nucleus, and (2) that the microglial response is dependent on nerve integrity and not on bouton behaviour.
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  • 27
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    Virchows Archiv 381 (1979), S. 189-203 
    ISSN: 1432-2307
    Keywords: Pseudomalignant ossifying myositis ; Ultrastructure ; Myofibroblasts ; Macrophages ; Pathogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Seven cases of pseudomalignant ossifying myositis with a typical clinical symptomatology have been reported. None of the cases had experienced an injury. All the lesions were intramuscular and all of them showed a zonal arrangement. Electron microscopy in three cases allowed the demonstration of cells showing morphological features of myofibroblasts and monocytic cells of the macrophage type. These previously unreported features together with the zonal pattern of the lesions indicate their reparative nature.
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  • 28
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    Virchows Archiv 382 (1979), S. 191-200 
    ISSN: 1432-2307
    Keywords: Rheumatoid arthritis ; Muscle spindles ; Neuromuscular spindles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural features of muscle spindles were studied in biopsy material from 100 patients suffering from classical rheumatoid arthritis. Thickening of the outer capsule, increased amount of extracellular ground substance within the inner capsule, and marked thickening of the basement membrane of capillary blood vessels supplying the muscle spindles were observed. Chronic inflammatory cells and macrophages were present within the spindles. Changes affecting the intrafusal muscle fibres were also seen. They were manifest as atrophy and degeneration of the intrafusal muscle fibres, absence of the specialised junctional complexes, and of the intercellular bridges, microladders and satellite cells. It is suggested that the changes affecting the intrafusal muscle fibres are probably secondary. Damage to the myelinated nerves was present, while the sensory and motor nerve endings were well preserved.
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  • 29
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    Virchows Archiv 385 (1979), S. 77-91 
    ISSN: 1432-2307
    Keywords: Ultrastructure ; Ovary ; Clear cell carcinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of an ovarian clear cell carcinoma in a 65 year old woman was analysed. The tumor cells were of both clear and “hobnail” types. Both were characterized by the presence of short microvilli, abundant glycogen granules, a well-developed granular endoplasmic reticulum and Golgi apparatus, scanty lysosomes and very few lipid bodies. The tubules and gland-like spaces were always separated from the stroma by a basement membrane. At ultrastructural level the tumor cells do not resemble at all those of clear cell renal carcinomas. On the other hand, their submicroscopic features are strongly similar to those of the clear cell tumors found elsewhere in the female genital tract, emphasizing therewith their very probable müllerian origin. It is recommended to eliminate the term “mesonephroma ovarii” to designate the clear cell carcinomas of the ovary.
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  • 30
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    Virchows Archiv 381 (1979), S. 313-329 
    ISSN: 1432-2307
    Keywords: Bronchial carcinoids ; Different types ; Cells of origin ; Ultrastructure ; Histology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Seven of eleven bronchial carcinoids investigated showed cells with small granules resembling P cells which have already been described in human fetal and adult lung; two of these P cell tumours showed distinctive paraganglioid features. One tumour showed peculiar ultrastructural findings resembling closely those previously reported by Black (1969) in a so called “pulmonary oncocytoma”. Three remaining cases showed large secretory granules resembling those of type 3 cells already described by Hage (1973 b) in bronchial carcinoids; one of these tumours produced large amounts of 5-hydroxytryptamine (5HT). It is concluded that, on cytological grounds, at least two types of tumours can be distinguished among bronchial carcinoids, i.e. P cell and type 3 cell tumours. Moreover, two varieties of P cell carcinoids have been recognized, showing either the less frequent and more distinctive paraganglioid structure or the more common trabecular structure.
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  • 31
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    Virchows Archiv 385 (1979), S. 93-101 
    ISSN: 1432-2307
    Keywords: Angioma ; Lung ; Carcinoma ; Pneumocytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Elektronenmikroskopische Untersuchung eines sog. sklerosierenden Hämangioms der Lunge, das im Oberlappen einer 32jährigen Frau zufällig entdeckt wurde. Der seltene gutartige Tumor, der lichtmikroskopisch wegen seines Gefäßreichtums an ein Hämangiom erinnert, zeigt elektronenmikroskopisch eine eindeutige epitheliale Struktur. Die Geschwulst entwickelt sich möglicherweise aus unreifen Pneumocyten. Histogenese sowie differential-diagnostische Probleme (Verwechslungsmöglichkeit mit Carcinom) werden diskutiert.
    Notes: Summary Electron microscopy of a sclerosing angioma of the lung, a coincidental finding in the upper lobe of a 32-year-old woman. The rare, benign tumor, whose vascular proliferation by light microscopy is reminiscent of an angioma, exhibits a clear epithelial structure by electron microscopy. The tumor may develop out of immature pneumocytes. The paper discusses histogenesis and problems of differential diagnosis (potential confusion with carcinomas).
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  • 32
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    Virchows Archiv 381 (1979), S. 121-139 
    ISSN: 1432-2307
    Keywords: Myxofibrosarcoma ; Fibroblast ; Histiocyte ; Myofibroblast ; Sarcoma ; Soft tissue tumour ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study of 11 myxofibrosarcomas is presented. The tumours were graded light-microscopically on a four-point scale according to cellularity, cell atypia and mitotic activity, as described in a previous paper: 3 were grade I, 2 grade II, 4 grade III and 2 grade IV. Fibroblast-like and myofibroblast-like cells predominated in the grade I and II tumours, while histiocyte-like cells were relatively few; in grade III and IV tumours histiocyte-like cells predominated. The fibroblast-like cells were spindle-shaped with fairly smoothly outlined nuclei, and contained abundant parallel membranes and wide cisternae of endoplasmic reticulum. The histocyte-like cells were irregular in shape and showed indented nuclei with large nucleoli and coarse, peripherally arranged clumps of heterochromatin. The cytoplasm of these cells showed prominent pseudopodiae, microvillous projections, conspicuous systems of vesicles and vacuoles, inclusions of lipid and pigment, numerous lysosomal structures and large digestive vacuoles indicating auto- and exophagocytosis. The myofibroblast-like cells showed abundance of parallelly arranged cytoplasmic microfilaments with dense body-like structures and condensation at the plasmic membrane. Occasional cells appeared to be intermediate forms and primitive looking, undifferentiated cells were also encountered. A few multinucleated tumours cells were seen in the grade IV tumours. Thus, the present study shows the composite fibroblastic, myofibroblastic and histiocytic character of the tumour cells of myxofibrosarcoma; the grade III and IV tumours, with a tendency to contain solid areas, seem to be closely related to the pleomorphic type of malignant fibrous histiocytoma.
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  • 33
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    Virchows Archiv 381 (1979), S. 159-178 
    ISSN: 1432-2307
    Keywords: Giant cell tumor ; Ultrastructure ; Acid phosphatase ; Lysosomes ; Bone tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Eleven benign giant cell tumors of bone were studied in the electron microscope, and the fine structural localization of acid phosphatase was elucidated. Three distinct cell types are always present in these tumors: stromal cells type 1; stromal cells type 2; and multinucleated giant cells. Small mononuclear cells may also occur, but are not likely to be actively participating in the neoplastic process. The range of variability in the fine structure of the different cell types constituting this tumor has been established. Variations in appearances include: a) presence of nuclear pseudoinclusions in stromal cells type 1 and multinucleated giant cells; b) aberrations in the structure of the rough surfaced endoplasmic reticulum in the same cell types; c) occurrence of ruffled borders, ectoplasmic layers and cytoplasmic labyrinths containing acid phosphatase in the giant cells. Some giant cells show evidence of marked phagocytic activity and contain large and numerous residual bodies carrying acid phosphatase. The significance of the interrelations between the different cell types are discussed and the possible role of stromal cells type 2 in immunological mechanisms directed against the tumor cells are mentioned.
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  • 34
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    European archives of oto-rhino-laryngology and head & neck 224 (1979), S. 31-35 
    ISSN: 1434-4726
    Keywords: Intracellular potentials ; Ultrastructure ; Hair cells ; Labyrinth receptors ; Reptilia (Crocodilia, Gekkonidae)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Different biopotentials, following a mechanical stimulus, were recorded from single hair cells of the reptilian labyrinth, with electronoptically circumscript localizations: 1. From the apical cell pole, the receptor potential, intracellular or from the ciliary surface, within the physiological range proportional to stimulus amplitude, frequency or phase, without delay, and with no real threshold of mechanosensitivity, as measured by ciliary displacement amplitude or velocity. 2. From the synaptic zone, in the basal region of the hair cell, or from contacting nerve endings, the synaptic potentials, local excitatory or inhibitory processes, respectively, with measurable latencies and with non-linear distortion. 3. From the (dendritic) endings of the first afferent neuron (or neurons), spike-shaped action potentials, synchronized by the (excitatory) synaptic potentials. Characteristic curves were plotted as a quantitative representation of the mechano-electric input-output relations of the different types of hair cells. For proceeding morphological and physiological system analysis, the comparison of the different submammalian inner-ear receptor systems gives us some new possibilities of a closer correlation between ultrastructure and function.
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  • 35
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    European archives of oto-rhino-laryngology and head & neck 225 (1979), S. 57-65 
    ISSN: 1434-4726
    Keywords: NZB/NZW-Maus ; Ultrastruktur ; Submandibulare Speicheldrüse ; Lymphocyten ; Autoimmunes Leiden ; NZB/NZW mouse ; Ultrastructure ; Submandibular gland ; Lymphocytes ; Autoimmune disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary An electron microscopic study of the submandibular salivary gland lesion occurring in the NZB/NZW F1 hybrid mice was performed, and the findings were discussed and correlated to the autoimmune salivary gland disease observed in patients with Sjögren's syndrome. Within the submandibular salivary gland of this mouse strain focal infiltrates of mononuclear inflammatory cells were observed. Lymphoid cells were observed inside the basal lamina of acini and ducts, leading to destruction of these glandular units. The typical duct cell proliferation found in the autoimmune sialoadenitis of Sjögren's syndrome with the formation of the typical epimyoepithelial islands was not found in the submandibular glands of NZB/NZW mice.
    Notes: Zusammenfassung Eine elektronenmikroskopische Untersuchung der bei den NZB/NZW F1 hybriden Mäusen vorkommenden Veränderungen in den submandibularen Speicheldrüsen wurde durchgeführt, und die Befunde wurden diskutiert und korreliert mit dem autoimmunen Speicheldrüsenleiden, das bei Patienten mit Sjögrens-Syndrom beobachtet wird. In der submandibularen Speicheldrüse dieses Mäusestammes wurden begrenzte Infiltrationen mononuklearer inflammatorischer Zellen beobachtet. Die mononuklearen Zellen wurden hauptsächlich als lymphoide Zellen identifiziert. Außerdem wurden innerhalb der Lamina basilaris von Drüsen und Drüsengängen lymphoide Zellen beobachtet, die zur Zerstörung dieser Drüseneinheiten führen. Darüber hinaus wurde der typische Zuwachs der Drüsengangszellen, der bei der autoimmunen Speicheldrüsenentzündung des Sjögrens-Syndroms vorkommt und die Form von typischen epimyoepithelialen Inseln annimmt, in den submandibularen Drüsen der NZB/NZW-Mäuse nicht vorgefunden.
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  • 36
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    Journal of cancer research and clinical oncology 95 (1979), S. 225-232 
    ISSN: 1432-1335
    Keywords: Cultured tumour cells ; Ultrastructure ; 3-D Colonies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cultured hepatocellular carcinoma cells were studied during anchorage-independent growth in semi solid medium (Methocel). The regular occurrence of mitotic figures both at the surface and within the colonies precludes the possibility of such colonies being formed by re-aggregation. The estimated population doubling time in the three-dimensional (3-D) colonies is consistent with those two-dimensional of (2-D) colonies. Structures resembling bile canaliculi were observed between the closely opposed membranes from the well packed adjacent cells. Cell surface and ultrastructural features of the colonies and individual cells are presented and comparisons made with 2-D growth of normal and malignant liver cells in vitro. The formation of 3-D colonies may not only be an assay for transformed cells but also for predicting the type of tumors produced by re-innoculation of the in vitro transformed cells.
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  • 37
    ISSN: 1615-6102
    Keywords: Ciliata ; Crystals ; Euplotes ; Lithosomes ; Microanalysis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the cytoplasm of the marine ciliateEuplotes vannus, there exist two conspicuous types of membrane bound inclusions: 1. irregularly shaped crystals which are highly anisotropic; 2. globular lithosomes characterized by concentrically arranged layers of deposits which exhibit only faint birefringence. Normally, both structures form distinct accumulations. Energy dispersive X-ray microanalysis of these accumulations reveals a high content of calcium and phosphorus, besides magnesium, sulphur and chlorine. Analysis of cell areas devoid of the inclusions show significantly lower calcium- and phosphorus-peaks.
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  • 38
    ISSN: 1432-0827
    Keywords: Bone resorption ; Osteogenesis ; Fish bone ; Osteocytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The comparative ultrastructure of fish bone osteogenesis and resorption induced by scale removal was described in the osteocytic (cellular-boned)Carassius auratus and the anosteocytic (acellular-boned)Tilapia macrocephala. Osteocytes, present in osteocytic bone, were lacking in anosteocytic bone. In osteocytic bone the osteoblast secreted a collagenous preosseous matrix in which it became enmeshed and then was termed a preosteocyte. When the preosseous matrix mineralized, the preosteocyte was termed an osteocyte and was completely surrounded by bone. In anosteocytic bone the osteoblasts receded from the mineralizing front and never became trapped as osteocytes. During resorption, types A and B resorptive cells, present in both bone types, invaded the matrix and demineralized the osseous zone. These cells were characterized by large amounts of granular endoplasmic reticulum and intracellular inclusions containing crystal-like material. Although functionally similar to mammalian osteoclasts, these cells lacked a characteristic ruffled border and were not multinucleated. The osteocytes of cellular bone did not appear to be involved during demineralization.
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  • 39
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    Research in experimental medicine 176 (1979), S. 69-79 
    ISSN: 1433-8580
    Keywords: Skeletal muscle ; CO2-laser ; Surgery ; Ultrastructure ; Rat ; Skelettmuskelfaser ; CO2-Laser ; Chirurgie ; Ultrastruktur ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Zustand der dorsalen Haut und des darunterliegenden Muskelgewebes der Ratte wurde unmittelbar nach CO2-Laser-Schnitten mit Hilfe von licht- und elektronenmikroskopischen Methoden untersucht. In der subkutanen Skelettmuskelschicht konnte eine erhöhte Empfindlichkeit des Gewebes festgestellt werden, die in einer ausgeprägten Abfolge von Zellveränderungen ihren Ausdruck findet. Diese Schädigungen werden hauptsächlich den thermischen Effekten der Laserstrahlung zugeschrieben. Die Bedeutung dieser Untersuchungsergebnisse in Hinblick auf die Verwendung von Laser in der Chirurgie wird besprochen.
    Notes: Summary The immediate effect of CO2-laser incision to the dorsal skin and underlying muscular tissue of rats was studied by light and electron microscopical methods. In the subcutaneous layer of skeletal muscle cells an increased susceptibility was found, resulting in distinct zones of cellular changes which are attributed mainly to thermal effects of the laser beam. The importance of these findings for the surgical application of lasers is discussed.
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  • 40
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    Virchows Archiv 384 (1979), S. 307-324 
    ISSN: 1432-2307
    Keywords: Calcifying odontogenic cyst ; Dysplastic dentin ; Hornified cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four new cases of calcifying odontogenic cyst (COC) were studied by light- and electronmicroscope. The ages of the patients were between 20 and 68 years. Three cysts were located in the maxilla, the other was in the mandible. The history of two patients was followed up for five and ten years respectively. The longer the history the bigger were the cysts. All cysts showed histologically identical alterations of the epithelium with 1) a pronounced cylindrical basal cell layer, 2) cells resembling stellate reticulum, and 3) ghost cells. So called dysplastic dentin was laid down in the connective tissue only in the two cases with a long history. Ultrastructurally the odontogenic epithelium of all cysts showed keratinization similar to the epidermis. Two types of keratinization are known to occur in the epidermis, soft keratinization with keratohyalin granules in ortho- and parakeratosis, and hard keratinization without keratohyalin granules in nails (horn). Both types of keratinization occur in odontogenic epithelium. The COC is an example of hard keratinization. Ghost cells form prekeratin which in turn becomes horn and is found in areas of confluent ghost cells and in the so called dysplastic dentin. We conclude that the alteration of odontogenic epithelium in COC and in special odontogenic tumors is a secondary phenomenon resembling ortho- and parakeratosis.
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  • 41
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    Virchows Archiv 384 (1979), S. 347-355 
    ISSN: 1432-2307
    Keywords: Exfoliation syndrome ; Non-glaucomatous eye ; Trabecular meshwork ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The trabecular meshwork of a non-glaucomatous eye with the exfoliation syndrome was investigated. The exfoliation material was found mainly in massive deposits in the subendothelial region of the outer and inner wall of Schlemm's canal, in the cribriform area and the uveal meshwork. The other alterations of the trabeculum corneosclerale corresponded to the age of the patient. The concept that the accumulation of exfoliation material is an important pathogenetic factor in the development of glaucoma was not confirmed by this study.
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  • 42
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    Virchows Archiv 384 (1979), S. 93-102 
    ISSN: 1432-2307
    Keywords: Primary aldosteronism ; Adrenal adenomata ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adenomata taken from 25 patients with primary aldosteronism were observed by electron microscopy. The cells in the adenoma had a well developed agranular endoplasmic reticulum but granular endoplasmic reticulum was not prominent. Most of the mitochondria resembled those in the cells of the zona glomerulosa, suggesting that the adenomata which caused primary aldosteronism are derived from this zone. Spironolactone bodies were found in the cells of the adenoma from a patient who received spironolactone. Their appearance was identical to that descrived in previous reports.
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  • 43
    ISSN: 1432-2307
    Keywords: Hexachlorobenzene ; Liver ; Ultrastructure ; Porphyrins ; Smooth endoplasmic reticulum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Groups of female rats were treated orally with 0.5, 2.0, 8.0, and 32 mg/kg hexachlorobenzene twice a week for 203 days. The liver content of hexachlorobenzene was found to be dose-dependent. In the animals treated with the highest dose the concentration was 273 μg/g hexachlorobenzene. In the fresh and fixed hepatic tissue of the treated animals pink fluorescence was observed. Electron microscopy revealed a dose dependent enlargement of all hepatocytes due to proliferation of the SER in the centrolobular area or to increased glycogen deposits (β- or α-particles) and SER in the intermediary and periportal area. Numerous porphyrin deposits and siderosomes, intimate disorganisation and moderate dislocation of the RER and a moderate enlargement of bizarre-shaped mitochondria were recognized. The relationship between porphyrin crystals and mitochondria on the one hand and between SER and glycogen deposits on the other is discussed.
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  • 44
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    Virchows Archiv 382 (1979), S. 201-216 
    ISSN: 1432-2307
    Keywords: Meningioma ; Ultrastructure ; Classification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We examined 23 meningiomas by electron microscopy. In each case it was possible to distinguish certain cells with epithelial features (desmosomes, microfilaments, interdigitating extensions) and others with fibroblastic features (collagen fibers). Others cells of transitional form were also seen. The proportion of these cellular types is variable, making it possible to classify meningiomas into seven types progressing gradually from a purely epithelial type to a purely fibroblastic one. We found no important ultrastructural abnormalities in the cells. These case reports confirm the uniqueness of meningiomas, which are composed of variously shaped cells but have their origin from a single cellular type. This has double potentiality for fibroblastic and epithelial differentiation.
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  • 45
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    Virchows Archiv 382 (1979), S. 217-226 
    ISSN: 1432-2307
    Keywords: Axonal swelling ; Spheroid ; Dystrophic axon ; Ultrastructure ; Human gracile nucleus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The morphology of the spheroids in human gracile nuclei was studied by light and electron microscopy. Various spheroids encountered in the present study could be classified into three types based on the internal structure: The first one was chiefly composed of many irregular homogeneous dense bodies, multivesicular bodies and mitochondria. The dense bodies seemed to deposit multicentrically in an axon in the early stage of “balloon” formation and coalesce to form larger ones. The second was characterized by a marked accumulation of closely approximated mitochondria and dense concentric bodies. In the third the most characteristic findings were neurofibrillary accumulation and aggregations of dense bodies. These findings showed some divergence from those of dystrophic axons and the last two mimic those of degenerative or regenerative axons, which suggested that axonal swelling (including dystrophic axon) is not characteristic reaction of specific disease but rather nonspecific one to a variety of noxious stimuli. With light microscope, it was difficult to distinguish balloons with different structures since they were quite diverse and manifold in their shape, size, appearance and stainability. Intra-axonal corpora amylacea were seen in most cases and their incidence appeared to be nonspecific for any diseases.
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  • 46
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    Virchows Archiv 382 (1979), S. 237-243 
    ISSN: 1432-2307
    Keywords: Giant cell tumors of tendon sheath ; Soft tissue tumors ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A benign, but aggressive, giant cell tumor of tendon sheath developed over a period of 20 years into a metastasizing, histologically malignant giant cell tumor. Ultrastructure of the malignant tumor showed the same five cell types as described in giant cell tumors of tendon sheath. Even the same crystals were identified in the osteoblast-like and osteoclast-like cells. It therefore appears reasonable to assume that giant cell tumors of tendon sheath indeed are neoplasms with a malignant potential and not an inflammatory reaction of synovial cells as previously suggested. Both the benign and malignant tumors seem to be of mesenchymal derivation with partial osseous differentiation. No ultrastructural similarities with fibrous histiocytoma were apparent.
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  • 47
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    Virchows Archiv 383 (1979), S. 181-193 
    ISSN: 1432-2307
    Keywords: Graves' disease ; Preoperative treatment ; Ultrastructure ; Antithyroid drug treatment ; Lithium ; Cellular involution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This electron microscopic study is based on 12 cases of toxic goiter treated preoperatively with iodide, thionamides and lithium. Essential features of Graves' disease include hypertrophy of the follicular epithelium, papillary follicular infoldings and frequently, lymphocytic infiltration and fibrosis. After preoperative therapy most thyroid glands show involutional changes of varying degree with reaccumulation of colloid and flattening of the follicular epithelium. In a small number of histologically examined cases (n=84) colloid goitre (13%) and nodular goitre (8%) were noted. Lymphocytic infiltration and interstitial fibrosis do not show any correlation with preoperative treatment. Ultrastructurally, different stages of cellular involution are seen. The hypertrophic follicular cell shows an increased cell surface with numerous long microvilli and some pseudopodia at the apical border and an occasionally thickened, basal lamina. The cytoplasm contains a well developed system of organelles which synthesizes (rough endoplasmic reticulum, Golgi apparatus, cytoplasmic vesicles) and degrades (colloid droplets, lysosomes) thyroglobulin. With increasing cellular atrophy we found cells to be reduced in size but to contain well developed thyroglobulin-synthesizing organelles. Finally, we observed completely atrophic flat cells with only a few organelles. There are at date no electron microscopic communications on lithiumpretreated thyroid glands. After lithium therapy characteristic changes are observed at the membranes of the cytocavitary system, which are often found to be thin and occasionally to be damaged. The rough endoplasmic reticulum is virtually deprived of ribosomes and the Golgi apparatus seems to be underdeveloped. The number of apical microvilli is reduced. The morphological findings following iodide-, thionamide- and lithium pretreatment in Graves' disease are discussed in light of recent biochemical results.
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  • 48
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    European archives of oto-rhino-laryngology and head & neck 225 (1979), S. 165-180 
    ISSN: 1434-4726
    Keywords: Lymphatics ; Larynx ; Lymphangioscopy ; Ultrastructure ; Lymphgefäße ; Kehlkopf ; Lymphangioskopie ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Lymphdrainage des menschlichen Kehlkopfes wurde an autoptischem und in vivo Material lymphangioskopisch registriert. Auf ultrastruktureller Ebene erfolgte die Untersuchung des morphologischen Aufbaus von Lymphkapillaren und Lymphsammelgefäßen. Im Elektronenmikroskop zeigt der Wandaufbau der Lymphgefäße des Kehlkopfes nur geringgradige Unterschiede zum Lymphgefäßsystem anderer Körperregionen. Diese Unterschiede finden sich vor allem im Wandklappenaufbau der Lymphsammelgefäße. Eine strenge Kompartmentierung einzelner Kehlkopfregionen läßt sich nicht nachweisen. Ausnahme bilden die Lymphkapillaren des freien Randes der Stimmlippe. Anastomosen der Lymphkapillaren und -sammelgefäße erlauben Mittelinien- und Kehlkopfetagen-überschreitende Lymphdrainagen. Diese bestehenden Kollateralabflüsse sind bei Behinderung der physiologischen Lymphdrainage von klinischer Bedeutung.
    Notes: Summary From post mortem and in vivo tissues, the lymphatic drainage of the human larynx has been evaluated by means of lymphangioscopy. The fine structure of lymphatic capillaries and collecting vessels was examined in an electron microscope study. At the ultrastructural level, the structural components of the laryngeal lymphatic vascular wall showed only minor differences when compared to other lymphatic tissues. These differences concerned the valvular morphology of the lymphatic collecting vessels. There was no evidence of specific lymphatic drainage for distinct laryngeal areas, with the exception of the lymphatic capillaries of the free margin of the vocal cords. On account of anastomoses of lymphatic capillaries and collecting vessels lymphatic drainage could cross over both the laryngeal midline and other laryngeal levels. In pathological conditions with impediment of lymphatic flow, these collateral communications are of clinical significance.
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  • 49
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    Archives of dermatological research 266 (1979), S. 239-251 
    ISSN: 1432-069X
    Keywords: Cutaneous malignant B-cell lymphoma ; Ultrastructure ; Semithin sections ; Cutane maligne B-Zell Lymphome ; Ultrastruktur ; Semidünnschnitte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Achtzehn Fälle von cutanen B-Zell Lymphomen von niedrigem Malignitätsgrad (gesichert durch Enzymcytochemie und Immuncytologie) wurden morphologisch mittels Semidünn- und Dünnschnitten unter-sucht. Vier Typen mit einem charakteristischen Muster von verschiedenen lymphoiden Zellen wurden gefunden: (1) Der lymphocytische Typ, überwiegend aus kleinen Lymphocyten bestehend; (2) der lymphocytoide (zentrocytische oder prolymphocytische) Typ, bei dem neben kleinen auch mittelgroße Lymphocyten (mit und ohne geknitterten Zellkernen) erscheinen; (3) der lymphoplasmacytoide Typ, bei dem neben kleinen und mittelgroßen Lymphocyten lymphoide Zellen mit unterschiedlich ausgeprägten Differenzierungsmerkmalen von Plasmazellen zu finden sind; sowie (4) der zentroblastische-zentrocytische Typ. Hier sind neben kleinen und mittelgroßen Lymphocyten auch Zentroblasten zu beobachten. Insgesamt stimmen die hier erhobenen morphologischen Befunde gut mit entsprechenden nodalen malignen Lymphomen überein. Die Anwendung moderner Klassifikationen von non-Hodgkin Lymphomen, insbesondere die »Kiel-Klassifikation«, erscheint daher auch für die Hautlymphome gerechtfertigt. Dünn- und Semidünnschnitte eignen sich bei der Routinediagnostik von derartigen Krankheitsfällen, vor allem dann, wenn mit Paraffinschnitten keine klare diagnostische Einordnung erfolgen konnte.
    Notes: Summary Eighteen cases of low grade malignant B-cell lymphomas (confirmed through enzyme cytochemistry and immunocytology) were investigated morphologically using thin and semithin sections. Four types with a characteristic pattern of different lymphoid cells were found: (1) the lymphocytic type, predominantly consisting of small lymphocytes; (2) the lymphocytoid (centrocytic or prolymphocytic) type, in which in addition to small lymphocytes medium-sized lymphocytes (with or without cleaved nuclei) are found; (3) the lymphoplasmacytoid type, where lymphoid cells with different degrees of similarity to plasma cells are seen as well as small and medium-sized lymphocytes; and (4) the centroblastic-centrocytic type, in which centroblasts are present next to small and medium-sized lymphocytes. These findings correlate well with the morphological observations in low-grade malignant B-cell lymphomas of the lymph nodes. Therefore, the application of modern classifications of non-Hodgkin lymphomas, such as the “Kiel Classification”, to cutaneous lymphomas appears justified. Thin and semithin sections are particularly useful in suspected cases of cutaneous malignant lymphoma, in which paraffin sections did not allow the diagnosis to be established.
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  • 50
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    Archives of dermatological research 266 (1979), S. 187-196 
    ISSN: 1432-069X
    Keywords: Disseminated lipogranulomatosis ; Farber's disease ; Sphingolipidoses ; Ceramide ; Ultrastructure ; Disseminierte Lipogranulomatose ; M. Farber ; Sphingolipidosen ; Ceramid ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine elektronenmikroskopische Untersuchung von 2 Hautläsionen bei einem aus der Türkei stammenden 2jährigen Jungen mit disseminierter Lipogranulomatosis (Farber) zeigte curvilineare Körper in Fibroblasten, Histiocyten und Endothelzellen, flache Membrananordnungen in Fibroblasten und Endothelzellen und spindelartige Körper in Schwann-Zellen. In peripheren Lymphocyten fanden sich nur Veränderungen der Mitochondrien (Schwellung und aufgebrochene Cristae), jedoch keine Einschlußkörper. Die intracytoplasmatischen curvilinearen Körper waren zahlreich und leicht nachweisbar. Sie scheinen für den M. Farber spezifisch zu sein, und es wird vorgeschlagen, sie “Farber Körper” zu nennen. Die Diagnose dieser Ceramidspeicherkrankheit, in der das histologische Bild weitgehend unspezifisch ist, kann daher ultrastrukturell bestätigt werden.
    Notes: Summary An ultrastructural investigation of two cutaneous lesions in a two-year-old Turkish boy with disseminated lipogranulomatosis (Farber) revealed curvilinear bodies in fibroblasts, histiocytes, and endothelial cells; “elongated membranes” in fibroblasts and endothelial cells; “zebra bodies” in endothelial cells; and spindle-shaped bodies in Schwann cells. In peripheral lymphocytes only alterations of mitochondria (swelling and ruptured cristae) but no inclusion bodies were found. Curvilinear bodies were numerous and easily identifiable; they appear to be characteristic of Farber's disease, and naming them “Farber bodies” is proposed. The diagnosis of this ceramide storage disease, in which the histological examination is relatively unspecific, can therefore be confirmed ultrastructurally.
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  • 51
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    Archives of dermatological research 264 (1979), S. 17-28 
    ISSN: 1432-069X
    Keywords: Malignant lymphoma ; Mycosis fungoides ; Sezary's syndrome ; Parapsoriasis en plaques ; Ultrastructure ; Semi-thin sections ; Maligne Lymphome ; Mykosis fungoides ; Sézary-Syndrom ; Parapsoriasis en plaques ; Ultrastruktur ; Semi-Dünnschnitt-Technik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Semi-Dünnschnitte erlauben eine bessere morphologische Differenzierung von lymphoiden Zellen als Paraffinschnitte. Zur Prüfung ihrer möglichen Bedeutung bei der Diagnostik von kutanen T-Zell-Lymphomen wurden folgende Untersuchungen durchgeführt: Lymphoide Zellen im cellulären Infiltrat von Hautläsionen bei Mykosis fungoides (11 Fälle), Sézary-Syndrom (9 Fälle) und Parapsoriasis en plaques (14 Fälle) wurden mittels Semi-Dünnschnitten von Epon-eingebetteten Biopsien quantitativ analysiert. Als Kontrollen wurden Biopsien von Epikutan-Test-Reaktionen, Kontaktdermatitis, initialer Psoriasis und Erythema chronicum migrans untersucht. Eine hohe Prozentzahl von Lutzner-(Sézary)-Zellen fand sich ständig beim Sézary-Syndrom und gelegentlich bei der Parapsoriasis en plaques. Bei der Mycosis fungoides überwogen lymphocytoide Zellen mit helleren Kernen als bei normalen Lymphocyten. In den meisten Tumorläsionen sowohl bei der Mycosis fungoides als auch beim Sézary-Syndrom fand sich eine erhöhte Prozentzahl von Immunoblasten. Lymphocyten waren der häufigste Zelltyp bei der Parapsoriasis en plaques und bei den Kontrollen. Diese Befunde könnten nützlich für die Diagnostik von Problemfällen sein, für die die Semi-Dünnschnitt-Technik als eine weitere Methode empfohlen wird.
    Notes: Summary Semi-thin sections are superior to paraffin sections for differentiating lymphoid cells. To test their possible significance in the diagnosis of cutaneous T-cell lymphomas, the following investigation was made: A quantitative analysis of lymphoid cells in the cellular infiltrate of cutaneous lesions of mycosis fungoides (11 cases), Sézary's syndrome (9 cases), and parapsoriasis en plaques (14 cases) was made using semi-thin sections of eponembedded biopsies. As controls biopsies of patch test reactions, contact dermatitis, initial psoriasis, and erythema chronicum migrans were studied. A high percentage of Lutzner (Sézary) cells was consistently found in Sézary's syndrome and occasionally in parapsoriasis en plaques only. In mycosis fungoides lymphocytoid cells with the nuclei, less dense than in normal lymphocytes were predominant. In most tumorous lesions of mycosis fungoides and of Sézary's syndrome an increased percentage of immunoblasts was noted. Normal lymphocytes were the most frequent cell type in parapsoriasis en plaques as well as in the controls. These findings may prove helpful in the diagnosis of problem cases, for which the use of semi-thin sections is recommended.
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  • 52
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    Archives of dermatological research 266 (1979), S. 143-159 
    ISSN: 1432-069X
    Keywords: Xanthoma ; Ultrastructure ; Lipid vacuoles ; Myelin figures ; Xanthoma ; Ultrastruktur ; Lipidvacuolen ; Myelinfiguren
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine elektronenmikroskopische Untersuchung von 10 Patienten mit normolipämischer Xanthomatose und von 2 Patienten mit hyperlipoproteinämischer Xanthomatose Typ IV und V ergab folgende Befunde: In allen Fällen wurden große Mengen von Histiocyten mit intracytoplasmatischen Lipid-Vacuolen, Lysosomen und Myelinfiguren gesehen. Dazu waren Mikrofilamente und Lipid-Vacuolen in einigen Fibroblasten zu beobachten. In sämtlichen Präparaten fanden sich mehrkernige histiocytäre Riesenzellen mit kristallinen Spalträumen sowie einige Mastzellen. Lipid-Vacuolen konnten auch in Schwannzellen, Endothelzellen und in Pericyten nachgewiesen werden. In einigen Endothelzellen und Pericyten beobachtete man Duplikaturen der basalen vaskulären Laminae und “rob-shaped” tubuläre Körperchen. Beim Xanthelasma palpebrarum und dem Xanthoma planum disseminatum fanden sich die histiocytären Schaumzellen in perivaskulärer Anordnung, wie bei den hyperlipoproteinämischen Xanthomatosen. Wir folgern, daß die ultrastrukturellen Aspekte in den verschiedenen Xanthomatosen im wesentlichen gleich sind, zumal große Ablagerungen von Fett in allen Zellen zu sehen sind. In den normolipämischen Xanthomatosen (Xanthelasma palpebrarum und Xanthoma planum disseminatum) ist die Art der Entstehung von Fettablagerungen vermutlich die gleiche wie bei den hyperlipoproteinämischen Xanthomatosen; sie unterscheiden sich jedoch von den Fettablagerungen beim Xanthoma disseminatum und beim Xanthogranuloma juvenile. Eine Einteilung der normolipämischen Xanthomatosen wird vorgestellt.
    Notes: Summary Electron microscopic aspects in ten cases of normolipidemic cutaneous xanthomatosis have been investigated. Two additional types IV and V hyperlipoproteinaemic xanthomatosis have also been included. Ultrastructural findings in all cases were similar. Abundant histiocytic cells with numerous intracytoplasmic lipid vacuoles, lysosomes, and myelin-figures, were the striking features. Moreover, in older lesions microfilaments and lipid vacuoles were found in some fibroblastic cells, as well as long space collagen around them. In some specimens we observed: giant multinucleated histiocytic cells, crystalline cleft-like spaces in histiocytes and some mastocytes with lipidic crystals in the extracellular space, as well as lipid vacuoles in Schwann cells, endothelial cells and pericytes. Rod-shaped tubulated bodies were found in some endothelial cells, with multiple basal vascular laminae. In xantelasma palpebrarum and in disseminate plane xanthoma the histiocytary foamy cells adopted a perivascular arrangement, as in hyperlipoproteinemic xanthomatosis. We concluded that ultrastructural aspects of different xanthomatosis are fairly similar as a consequence of the large amount of intracytoplasmic lipids accumulated in xanthomatous cells. In xanthelasma palpebrarum and in disseminated plane xanthoma this cell phase is reached by similar pathways to those for hyperlipoproteinemic xanthomatosis, whilst in xanthoma disseminatum and juvenile xanthogranuloma the pathways seem to be different. A classification of normolipidemic xanthomatosis is also provided.
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  • 53
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    Biotechnology and Bioengineering 21 (1979) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 54
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The morphology of dried Candida lipolytica yeast suspended in aqueous solutions (H2O, 0.4% NaOH, 2N HCl, and 6N HCl) and organic solvents (95% alcohol and acetone) was studied using a scanning electron microscope (SEM) and an optical microscope. The effect of high-pressure homogenization on cell-wall structure and cell clumps was also determined. The protein extractability, sedimentation property, and viscosity of cells subjected to different mechanical and chemical treatments were also investigaged. The dried yeast cells were in a spherical agglomeration consisting of 100s of closely bound cells. The clump was resistant to water, aqueous 2N HCl solution at 25°C, 95% alcohol and acetone, but vulnerable to 6N HCl, aqueous 0.4% NaOH solution, and homogenization. The homogenization of the cell suspension not only broke the clump but also cracked the cell-wall structure. The aqueous alkaline solution could have weakened the cell wall and increased the solubility of the protein released through the cracks in the cell wall. The destruction of the agglomeration and the cell-wall structure increased the hydration of the cell and thereby increased the stability of the suspension. The sedimentation and the viscosity of the cell suspension corresponded to the morphological changes and the extractability of protein in the cell suspensions with different treatments.
    Additional Material: 10 Ill.
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  • 55
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    Biotechnology and Bioengineering 21 (1979), S. 49-58 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The relationship between the dimensions of a microbe and the accumulation of that microbe in porous, inorganic structures has been determined. That relationship is dependent upon the cell dimensions, the mode of reproduction, and the pore diameter of the material. In order to achieve high accumulation of microbes that reproduce by fission, at least 70% of the pores of an inorganic carrier should have pore diameters in the range of one times the smallest major dimension through five times the largest major dimension of the cell. To achieve the highest accumulation of microbes that reproduce by budding, at least 70% of the pores should have pore diameters in the range of one times the smallest dimension of the cell and less than four times the largest cell dimension. These relationships were established by varying the physical parameters of the carriers as well as their chemical composition.
    Additional Material: 5 Tab.
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  • 56
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A two-stage aerobic continuous process is suggested for the conversion of poultry waste into a single-cell protein (SCP) product. The technical feasibility of the process is examined in this paper. Using bench-scale apparatus the approximate growth kinetics have been discovered. Possible modes of product recovery have been examined. The product consists primarily of a strain of Pseudomonas fluorescens which has a lysine-rich (∼9.3%) amino acid profile that could make this product an attractive feed ingredient for poultry diets.
    Additional Material: 6 Ill.
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  • 57
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    Biotechnology and Bioengineering 21 (1979), S. 39-48 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The hydroxysteroid dehydrogenases: β-HSDH, 20β-HSDH, and 3α-HSDH, were immobilized on CNBr-activated Sepharose. The effect of various immobilization conditions on the activity recovery and stability were examined. The presence of cofactor during the immobilization reaction increased the activity recovery (40-60% of the total) and also led to materials highly stable in the presence of organic solvents. For example, β-HSDH maintained 60% of its original activity two months after continuous use in the water-ethyl-acetate system. Kinetic experiments showed that the increase of the apparent Km values is poor and demonstrated that the organic solvent behaves as a weak inhibitor (ki 〉 0.2M) for the substrate. The immobilized enzymes lyophilized in the presence of sucrose had full activity restored even after several months storage at room temperature. Immobilized hydroxysteroid dehydrogenases were shown to be suitable for preparative transformation of steroids in water-organic solvent systems.
    Additional Material: 2 Ill.
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  • 58
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    Biotechnology and Bioengineering 21 (1979), S. 59-67 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The relationship between the dimensions of a spore and the accumulation of that microbe in a porous, inorganic structure has been determined. In order to achieve high accumulation of mycelial growth, at least 70% of the pores of an inorganic carrier should have pore diameters in the range of one times the smallest dimension of the fungal spore but less than about 16 times the largest dimension of that spore. This relationship was established by varying the physical parameters of the carriers as well as their chemical composition.
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  • 59
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    Biotechnology and Bioengineering 21 (1979), S. 69-88 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The primary consideration in fermentor design is the supply of oxygen to the growing microorganisms. The oxygen-transfer characteristics of a two-stage splitcylinder airlift tower were compared to those of a similar single-stage airlift tower of equal liquid volume using a sodium sulfite-air system. At superficial gas velocities, from 720 to 1200 cm/min, no difference in KLa was apparent. The KLa was significantly larger in the two-stage tower for a gas velocity between 1200 and 2728 cm/min. At 2728 cm/min a KLa of 25.2 min-1 was achieved in the two-stage system, and at 2262 cm/min the two-stage tower had a 54% larger KLa than the single stage. A comparison of dispersion-volume based KLa showed a 27% larger value at a gas velocity of 2262 cm/min. The performance ratios for the two-stage tower were larger than those for the single-stage tower at oxygen-transfer rates greater than 180 mmol/liter hr. A comparison of the data with literature values is presented.
    Additional Material: 10 Ill.
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  • 60
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    Biotechnology and Bioengineering 21 (1979), S. 89-109 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Glucose oxidase containing catalase was immobilized with a copolymer of phenylenediamine and glutaraldehyde on pumice and titania carrier to study the enzymatic oxidation of glucose in a differential-bed loop reactor. The reaction rate was found to be first order with respect to the concentration of limiting oxygen substrate, suggesting a strong external mass-transfer resistance for all the flow rates used. The partial pressure of oxygen was varied from 21.3 up to 202.6 kPa. The use of a differential-bed loop reactor for the determination of the active enzyme concentration in the catalyst with negligible internal pore diffusion resistance is shown. Catalyst deactivation was studied, especially with respect to the presence of catalase. It is believed that the hydrogen peroxide formed in the oxidation reaction deactivates catalase first; if an excess of catalase is present, the deactivation of glucose oxidase remains small. The mathematical model subsequently developed adequately describes the experimental results.
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  • 61
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    Biotechnology and Bioengineering 21 (1979), S. 111-129 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A time-optimal strategy for start-up of a chemostat has been established by applying Miele's extremization method based on Green's theorem. The start-up time is always minimized by traveling along the uppermost boundary of the set of admissible domains on the (vx, μ) phase plane. The solutions are batch culture for monotone increasing growth kinetics and exponentially fed-batch culture followed by batch culture for substrate-inhibition kinetics. A time-suboptimal start-up strategy, exponentially fed-batch culture operated the same μ as that of chemostate, is proposed as more feasible than and physiologically preferable to the time-optimal strategies. The complete set of equations of operations necessary for performing each of the optimal and suboptimal start-ups is formulated. Numerical comparisons on the basis of continuous operation giving maximum productivities of cell-mass outputs show that differences in times required for start-up between optimal and suboptimal strategies are small.
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  • 62
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    Biotechnology and Bioengineering 21 (1979), S. 147-151 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
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  • 63
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    Biotechnology and Bioengineering 21 (1979), S. 153-156 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
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  • 64
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    Biotechnology and Bioengineering 21 (1979), S. 131-146 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Most cellulosic substances contain appreciable amounts of cellulose and hemicellulose, which on enzymatic hydrolysis mainly yield a mixture of glucose, cellobiose, and xylose. In this paper, studies on the mechanisms of hydrolysis of bagasse (a complex native cellulosic waste left after extraction of juice from can sugar) by the cellulase enzyme components are described in light of their adsorption characteristics. Simultaneous adsorption of exo- and endoglucanases on hydrolyzable cellulosics is the causative factor of the hydrolysis that follows immediately after. It supports the postulate of synergistic enzyme action proposed by Eriksson. Xylanase Pretreatment enhanced the hydrolysis of bagasse owing to the creation of more accessible cellulosic regions that are readily acted upon by exo- and endoglucanases. The synergistic action of the purified exoglucanase, endoglucanase, and xylanase has been found to be most effective for hydrolysis of bagasse but not for pure cellulose. Significant quantities of glucose are produced in β-glucosidase-free cellulase action on bagasse. Individual and combined action of the purified cellulase components on hydrolysis of native and delignified bagasse are discussed in respect to the release of sugars in the hydrolysate.
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  • 65
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    Biotechnology and Bioengineering 21 (1979) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 66
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    Biotechnology and Bioengineering 21 (1979), S. 159-165 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Based on the hypothesis that discharge mechanisms are induced in highly illuminated thylakoid, we analyze an applied model, which overcomes the damage induced by outdoor solar radiation, partially shaded, air-bubbled, or stirred blue-green algae cultures. The blue-green alga, Oscillatoria sp., exhibits a maximum growth rate at a radiation intensity of 50 J/m2sec. The introduction of 0.1 sec dark periods shifts this peak up to 75 J/m2sec. The radiationless nature of the discharge mechanisms is discussed in accord with the low growth rates of both the experimental and control cultures at 40°C.
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  • 67
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    Biotechnology and Bioengineering 21 (1979), S. 167-171 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Endoglucanase (Cx cellulase) and cellobiase are often cross-contaminated in separation procedures by ion-exchange chromatography such as DEAE-cellulose. By using concanavalin A (Con A)-agarose chromatography, Cx cellulase and cellobiase from Trichoderma viride can be separated. Cx cellulase showed affinity toward Con A, indicating a glycoprotein containing α-D-mannopyransyl and α-D-glucopyranosyl end groups or internal 2-O-D-mannopyranosyl residues in sugar moieties. This method provides a way to estimate the quantities of Cx enzyme produced by T. viride and possibly by other organisms.
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  • 68
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    Biotechnology and Bioengineering 21 (1979), S. 173-179 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Xanthan biopolymer has been produced in a single-stage continuous fermentation with Xanthomonas campestirs NRRL B-1459, using a viscostal control method instead of the conventional chemostat method. A Bendix UltraviscosonThe mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned. sensed the fermentor viscosity, and the recorder-controller actuated the feed medium pump in an on-off control mode. Since all continuous fermentations eventually become contaminated or suffer culture variation, this work served also to demonstrate the effectiveness of the viscostat control. Neither the presence of a mold contaminant with specific growth rates lower than that of X. campestris, nor the presence of a bacterial contaminant of specific growth rate greater than X. campestris, affected the maintenance of constant viscosity in this control system.
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  • 69
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    Biotechnology and Bioengineering 21 (1979), S. 181-191 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Trichoderma can be cultured in stirred-tank fermentors on high (8%)cellulose concentrations without increasing the salt concentration of the medium when NH4OH is used to control pH and as a nitrogen source. Approximation 90% of the ammonia consumed by the organism can be added as NH4OH. The advantage of using high concentrations of cellulose is that culture filtrates with greater cellulase activity are obtained. The advantage of a low salts medium is that unwanted solutes in the final enzyme preparation are reduced. The appearance of cellulase in the medium occurs later than net ammonia uptake so that only 20% of the final amount of cellulase has appeared when 80% of the maximum amount of ammonia has been consumed.
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  • 70
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    Biotechnology and Bioengineering 21 (1979), S. 201-211 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The intrinsic rate of nitrification was observed in a batch reactor by eliminating external and internal diffusional resistances. The former were minimized by means of intense agitation, and the latter by mechanical rupture of the activated sludge flocs using high mixer rotational speeds. The optimum temperature and pH for the intrinsic nitrification rate were found to be 30-35°C and 8.0, respectively. Initial ammonium concentration was found to have a strong effect on the value of the kinetic parameters of the Michaelis-Menten rate expression at low ammonium levels. However, at high initial concentrations both parameters attained a constant maximum value that is independent of the initial substrate level.
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  • 71
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    Biotechnology and Bioengineering 21 (1979), S. 193-200 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Novel biomass support particles containing growing cells have been developed for use in large-scale fermentation processes. The characteristic size of the entrapped biomass is identical to that of the physical structure of the support particle, and particles can be produced of any size, shape, and density with a wide variety of microorganisms. Use of the particles in fermentors leads to high biomass concentration independent of throughput, predetermined biomass concentrations, the use of novel types of fermentor with advantageous performance characteristics, possibilities for the optimization of advantageous diffusion effects, and new procedures for biomass recovery.
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  • 72
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    Biotechnology and Bioengineering 21 (1979), S. 213-220 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A fermentor system with an external filtration loop has been developed to control the growth and sporulation of yeast in a single vessel. Excess growth medium, instead of being removed by centrifugation, is removed by filtration and replaced with acetate sporulation medium. The technique did give 80% sporulation after 20 hr, greatly improving the rate and degree of synchrony of sporulation and it also eliminated the contamination hazard of the conventional harvest technique, centrifugation, and resuspension of vegetative cells in sporulation medium. Furthermore it permits proper control of the environmental conditions throughout the growth, exchange, and sporulation phase. In this technique 100% recycle of biomass is achieved without any packing of the cells on the filter. This technique has wide application in the study of industrial fermentation that involves microbial differentiation such as the production of ergot alkaloids, bacitracin, and cephalosporin.
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  • 73
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    Biotechnology and Bioengineering 21 (1979), S. 221-251 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The biological rate equation that describes the overall rate of substrate uptake by microbial films has been extended to microbial flocs with the aid of a shape parameter. The “solid”- and liquid-phase diffusion limitations are explored and found to depend largely on a dimensionles characteristic size k21Vp/Ap. Procedures are discussed by which k21Vp/Ap can be determined from experimental data on the conversion efficiency in a completely mixed fermentor and measurements carried out on flocs recovered from the fermentor are assessed. Floc size distributions are shown to affect the performance characteristics of a fermentor when some of the flocs are sufficiently large to exhibit a diffusional limitation, and it is concluded that a single mean floc size (k21Vp/Ap)* is sufficient to characterize a given distribution, at least when all the flocs are geometrically similar. The mean floc size closely corresponds to the “surface” mean floc size of the floc size distributions.
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  • 74
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    Biotechnology and Bioengineering 21 (1979), S. 261-270 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Penicillium chrysogenum was immobilized in polyacrylamide gel prepared from 5% acrylamide monomers (85% acrylamide and 15% N,N′-methylene bisacrylamide). Penicillin produced from glucose by the immobilized mycelium was 17% of that produced by washed mycelium. However, the activity of penicillin production of the washed mycelium decreased with repeated use. On the other hand, the activity of the immobilized mycelium increased initially and decreased gradually with repeated use. The rate of oxygen uptake of the immobilized mycelium was about 30% of that of the washed mycelium. The immobilized mycelium required oxygen for the production of penicillin.
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  • 75
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    Biotechnology and Bioengineering 21 (1979), S. 253-260 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Chloroplasts of chinese mustard (Brassica campestris L.) were immobilized in polyacrylamide gel. A 8% polymer concentration was suitable for the immobilization. The activity of the carbon dioxide fixation of immobilized chloroplasts was 65% of that of free chloroplasts. The optimum conditions for the carbon dioxide fixation of immobilized chloroplasts were similar to that of native chloroplasts. However, immobilized chloroplasts were more stable under alkaline conditions and high temperatures than native chloroplasts. Light penetration of the gel was not a limiting parameter of the carbon dioxide fixation. The lifetime of immobilized chloroplasts was three times longer than that of free chloroplasts. 3-Phosphoglyceraldehyde and other compounds were produced continuously by immobilized chloroplasts.
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  • 76
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    Biotechnology and Bioengineering 21 (1979), S. 271-281 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: As part of a program to investigate the use of biological nitrogen fixation for fertilizer ammonia production, an investigation into the immobilization of the aerobic, nitrogen-fixing bacterium, Azotobacter vinelandii was undertaken. Immobilization was accomplished by adsorption onto an anionic exchange cellulose (Cellex E)with loadings as high as 1011cells/g resin. Immobilized cell preparations were tested under both batch and continuous-flow conditions. Nitrogenase activity as high as 4200 nmol/min g resin were observed as measured by the acetylene reduction assay. Immobilized cells retained their activity for as long as 177 hr in a continuous-flow reactor. Activity loss appeared to be related to the development of a variant strain.
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  • 77
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    Biotechnology and Bioengineering 21 (1979), S. 323-328 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 78
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    Biotechnology and Bioengineering 21 (1979), S. 297-315 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Work has been carried out on the production of citric acid by Aspergillus foetidus in single-stage continuous culture, operated under nitrogen-limiting conditions at dilution rates between 0.04 to 0.21 hr-1. Citric acid concentration increased rapidly as the dilution rate decreased and appears to be critically dependent on the pH in the culture vessel and the nitrogen concentration in the feed. A mathematical model based on a distinction between basic cells, which require nitrogen but do not produce citric acid, and stroage cells, which accumulate carbon and simultaneously produce citric acid, is proposed.
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  • 79
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    Biotechnology and Bioengineering 21 (1979), S. 317-321 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 80
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    Biotechnology and Bioengineering 21 (1979), S. 283-296 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The scope in improving enzyme productivities from the cellulose fermentation process is examined in laboratory-scale fermentors. The maximum productivity (30 IU/liter hr) is attained in a continuous-culture process with cell recycle using modified medium containing 0.5% cellulose. Optimum dilution rate and recycle ratio are determined as 0.025 hr-1 and 1.2, respectively, for the process. The system is analyzed and steady-state equations for predicting enzyme protein concentrations in the fermentor are developed. In fed-batch cultures, slow addition of cellulose at high concentrations can improve enzyme productivity by as much as 33% over a batch process. The scope and results of using modified medium for cellulase production are also presented.
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  • 81
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    Biotechnology and Bioengineering 21 (1979), S. 329-332 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 82
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    Biotechnology and Bioengineering 21 (1979), S. 333-336 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 83
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    Biotechnology and Bioengineering 21 (1979), S. 337-339 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 84
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    Biotechnology and Bioengineering 21 (1979), S. 341-344 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 85
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    Biotechnology and Bioengineering 21 (1979) 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 86
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    Biotechnology and Bioengineering 21 (1979), S. 345-355 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The location of the β-glucosidase activity in a whole culture broth of the thermophilic organism Thermoactinomyces has been studied. Little β-glucosidase activity was found in the culture filtrate, while the culture solids contained the major part of the activity of the whole culture broth. The activity does not appear to be adsorbed to the culture solids; rather there is evidence that it is an intracellular soluble enzyme(s). The pH and temperature optima for a crude β-glucosidase preparation were determined to be pH 6.5 and 50-55°C. Enzyme activity studies indicate that the same enzyme(s) accounts for the β-glucosidase and the cellobiase activities. The validity of using the filter paper activity of culture filtrates from Thermoactinomyces to predict the total saccharification of cellulosic materials to glucose is discussed.
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  • 87
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    Biotechnology and Bioengineering 21 (1979), S. 357-391 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The existence of rapid and slow transients in the continuous culture of microorganisms when limited by one of the nutrients is revealed on the basis of a new method of mathematical analysis that separates these rapid and slow transients. The slow transient occurs along one and the same line of slow movement (LSM) independent of the initial state of the culture. This line is situated in the “substrate concentration S - biomass concentration X” coordinate system and rigidly connects these concentrations. When the initial values of S and X do not lie on this line, the rapid process occurring before the slow one leads the culture to LSM. Arrival to LSM occurs owing to alteration of S at almost constant X. The biomass concentration is always a slow variable but tne substrate concentration is both a rapid and a slow variable. A number of regularities of this time hierarchy are analyzed. A comprehensive description of the dynamics of continuous cultivation of microorganisms including different ways of supplying limiting nutrients is presented. Phaseplane plots of microbial cultures and the families of isochrones (lines making it possible to determine exactlythe transient duration) are given. The isochrone theory is described in the appendix.
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  • 88
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    Biotechnology and Bioengineering 21 (1979), S. 393-416 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Ni powders coated by deposition of TiO2 or controlled oxidation to NiO develop substantial resistance to corrosion. Chymotrypsin immobilized to these coated Ni supports shows very high stability of activity on storage. Chymotrypsin immobilized by adsorption and glutaraldehyde crosslinking was fairly rapidly eluted under operational conditions in the presence of substrate. If 3-aminopropyltriethoxysilane (APS) was used to produce a covalent linkage, desorption of enzyme still occurred because of relatively unstable bonding of the silane to the oxide surface. A more stable attachment was produced by joining together many silane links with a layer of polyglutaraldehyde. The mechanism of action of APS as a coupling agent under these conditions is discussed. γ-Fe2O3, and particularly a Mn-Zn ferrite, are suitable magnetic support materials available with smaller particle sizes. Particles below 1 μm give the expected higher specific activities of immobilized enzymes.
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  • 89
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    Biotechnology and Bioengineering 21 (1979), S. 417-431 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The concept of solid retention time (SRT) was applied in the trickling-filter process. A rational model of the trickling-filter process employing activated-sludge-process operational parameters was presented. The design equation was developed as follows; 1/SRT = [(S0 - Sn)/X]·(F/V)·Y - kd, where SRT is the sludge retention time, S0 is the influent substrate concentration; Sn is the effluent substrate concentration; X is the total cell mass retained per unit filter volume; V is the total volume of the filter; F is the influent flow rate; Y is the cell yield, and kd is the cell decay rate. A laboratory-scale trickling-filter pilot plant treating synthetic sucrose waste-water was studied to verify the present design equation. The solid retention time was evaluated from the total slime mass (active and inactive) retained and the sludge wasted daily. It was found that the present design equation could be applied for designing the trickling-filter process by the application of SRT employed in the activated sludge process. Also, the SRT could be related to the hydraulic loading and influent substrate concentration for a given filter medium. The variation of SRT by the hydraulic loading at constant organic loading was observed and could be expressed by the mechanistic model. When SRT was maintained more than 12 days, it provided the highest five-day biological oxygen demand (BOD5) removal, minimum sludge production, and lowest sludge volume index (SVI) value. The present model does include both microbial growth kinetic concepts, which can be more practical and meaningful for the design of a trickling filter.
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  • 90
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    Biotechnology and Bioengineering 21 (1979), S. 433-442 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A variety of diploid human fibroblast lines have been successfully grown to high densities (〉106 cell/ml) on recently developed microcarriers. Interferon induction using poly I·poly C and a superinduction procedure resulted in yields greater than 10,000 units/ml with one cell line. A direct comparison of microcarrier cultures to roller bottle cultures showed equivalent interferon yields on a per cell basis and some apparent differences relating to optimum inducer concentrations and kinetics of interferon accumulation.
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  • 91
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    Biotechnology and Bioengineering 21 (1979), S. 443-459 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: α-Chymotrypsin was light sensitized by acylating with cis-cinnamoyl ester, a substrate interconvertible to the trans form by ultraviolet (UV) light. The degree of acylation by this method was complete leaving no residual activity of the enzyme. Upon UV irradiation the inhibited enzyme regained about 70% of its original activity, thereby adding light-sensitiveness to the proteolytic enzyme. In seeking a photographic application of the light-sensitized enzyme, a pigmenting enzyme was incorporated with it. The coupled enzyme system was shown to exhibit a light signal in the form of dark pigment slurry.
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  • 92
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    Biotechnology and Bioengineering 21 (1979), S. 461-476 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Based upon its superior catalytic activity for H2O2 decomposition, a bituminous coal-based activated carbon was selected for investigations of pretreatment and enzyme immobilization methods. Pretreatments considered include acid washing, exposure to strong oxidizing agents, contact with concentrated peroxide solutions, nitration and amination, isothiocyanate derivatization, silanization, and stearic acid coating. Effects of these pretreatments on morphology and trace-metal content of the carbon pellets have been studied using scanning electron microscopy and dispersive analysis of x rays. Immobilization of glucoamylase by adsorption, glutaraldehyde crosslinking, and covalent attachment to carbon activated by water-soluble diimide or diazotization have been examined. These different enzyme-carbon catalysts have been characterized by their enzyme loading, enzyme activity, catalytic activity for H2O2 decomposition, or combinations of these measures of performance.
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  • 93
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    Biotechnology and Bioengineering 21 (1979), S. 503-504 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 94
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The immobilization of aminoacylase (N-acylamino acid amidohydrolase, EC 3.5.1.14) was investigated by using tannin immobilized on aminohexyl cellulose. The most active immobilized aminoacylase was obtained when aminoacylase was adsorbed to the immobilized tannin in a weak alkaline medium containing sodium chloride and n-butanol at 37°C. The activity of the immobilized tannin-aminoacylase complex per unit volume was five times higher than that of the DEAE-Sephadex-aminoacylase complex used for industrial production of L-amino acids in our plants. The half-life of the immobilized tannin-aminoacylase complex was 20 days under continuous operation at a high concentration of substrate; on the contrary, that of the DEAE-Sephadex-aminoacylase complex was 0.5 days.
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  • 95
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    Biotechnology and Bioengineering 21 (1979), S. 487-502 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The rate kinetics of growth and acid phosphatase formation in the batch culture of Saccharomyces carlsbergensis LAM 1068 was studied under varying degrees of phosphate limitation. The mathematical model that was developed is concerned with the time lag for exponential growth, the biphasic growth on a substrate (glucose) and its product (ethanol), sustained growth on conservative phosphate, and the derepression of acid phosphatase. The numerical calculations using appropriate parametric constants successfully described the variation in the cell mass, glucose, ethanol, and inorganic phosphate concentrations, and the enzyme activity of acid phosphatase during aerobic growth of S. carlsbergensis under five different conditions of phosphate starvation. A simulation study revealed that the optimum initial phosphate concentration in the medium giving a high productivity of acid phosphate was 2.0 mg phosphorus/g glucose liter.
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  • 96
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    Biotechnology and Bioengineering 21 (1979), S. 505-512 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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  • 97
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    Biotechnology and Bioengineering 21 (1979), S. 513-518 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 98
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    Biotechnology and Bioengineering 21 (1979), S. 525-532 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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    Biotechnology and Bioengineering 21 (1979) 
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    Keywords: Chemistry ; Biochemistry and Biotechnology
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    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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