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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 239 (1984), S. 133-144 
    ISSN: 1434-4726
    Keywords: Esthesioneuroblastoma ; Intermediate filaments ; Secretory granules ; Ultrastructure ; Immunohistology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of esthesioneuroblastoma, the pathological diagnosis of which almost always causes great difficulties, was investigated ultrastructurally, biochemically, and immunohistologically, using antibodies against the five known types of intermediate filaments [keratin, vimentin, desmin, glial fibrillary acidic protein (GFAP) and neurofilaments]. The tumour cells did not react with antibodies against any of the five intermediate filament proteins. Ultrastructural investigations showed dense cored secretory granules in the cytoplasm and cell processes. Thus, immunohistology offers by “exclusion” a differential diagnosis to avoid often misdiagnosed tumours (undifferentiated carcinomas, embryonal rhabdomyosarcomas, and malignant lymphomas), since carcinomas react with antikeratin, embryonal rhabdomyosarcomas with antibodies to desmin and malignant lymphomas show immunofluorescence with antibodies to vimentin. The biological behaviour (age distribution, tendency to metastasize), the normal values of biochemical parameters, homovanillic acid and vanilmandelic acid (HVA, VMA), and the absence of neurofilaments distinguish this type of tumour from the peripheral sympathetic neuroblastoma.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-2307
    Keywords: Granulocytic sarcoma ; Chloroma ; Meningeal sarcoma ; Ultrastructure ; Myelogenous leukemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An unusual case of meningeal granulocytic sarcoma without evidence of Leukemia is presented. The patient, a 40 year old female, presented with a chronic subdural haematoma. Three months later a large meningeal tumor was discovered adjacent to the previous haematoma and was found to be a granulocytic sarcoma by the use of electron microscopy. The tumor was treated by surgical excision followed by radiotherapy and chemotherapy. The patient remains free of symptoms and without evidence of leukemia in the peripheral blood or bone marrow 9 months after the diagnosis was established. The ultrastructural findings in the tumor and diagnostic difficulties often encountered are emphasized.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0533
    Keywords: β-Galactosidase and neuraminidase deficiency ; Neuronal inclusion bodies ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An autopsy case of a Japanese male with familial β-galactosidase and neuraminidase deficiency is reported. The clinical picture was characterized by adult onset, a gargoyle-like face, cerebellar ataxia, myoclonus, convulsions, retinal degeneration and cortical blindness. Histopathologically, most neurons seemed to have become degenerated in the whole cerebral cortex. Moreover, the calcarine cortex appeared spongy with depopulation of nerve cells. Stuffed neurons or neuronal storage changes were found throughout the brain, especially in the motor nuclei of the spinal cord and brain stem. The inclusions in the stuffed neurons revealed various profiles on the electron microscope. They were composed of membranous lamellar and/or multilamellar structures, often accompanying vacuoles and reminiscent of lipofuscin-like profiles.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0533
    Keywords: Ependymoma ; Rat ; Ethylnitrosourea ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Tumors of the central nervous system (CNS) in Sprague-Dawley and Lewis rats were induced transplacentally by a single intraperitoneal (IP) injection of 10–25 mg/kg ethylnitrosourea (ENU) on days 16–20 of gestation. Light-microscopic examination revealed that 22% of these tumors could be diagnosed as ependymomas, anaplastic ependymomas (ependymoblastomas), or mixed tumors revealing both oligodendroglioma and anaplastic ependymoma tissues if the criteria of accepted classifications were followed. Electron-microscopic examination, however, demonstrated that the ependymoma and the anaplastic ependymoma-like tissue in ENU-induced tumors lacked ependymal features, such as basal bodies, cilia, complicated junctional complexes, microvilli, etc. This tissue type was repetitious, always being composed of cells arranged in groups, cords, and rosette-like (pseudorosette) formations. In the pseudorosettes, the cell nuclei were polarized at the periphery and the cytoplasm contained numerous polyribosomes, occasional short microtubules and usually a few small dense-core vesicles. The center of the pseudorosettes showed numerous slender interdigitating processes interconnected by maculae adherens. The tips of these processes showed vesicular degeneration. The cells arranged in groups or cords and perivascular rosettes revealed identical ultrastructure, but they were not polarized. The present findings indicate that the socalled ENU-induced ependymomas and anaplastic ependymomas are not true ependymal tumors, but rather primitive neuroepithelial neoplasms with some features of oligodendroglioma.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 62 (1983), S. 1-14 
    ISSN: 1432-0533
    Keywords: Pituitary adenomas ; Immunohistology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An analysis is presented of the immunohistological and ultrastructural features in a series of 118 surgically removed pituitary adenomas all of which were studied immunohistologically using antisera to growth hormone (GH), prolactin (PRL) ACTH, βFSH, βLH and βTSH, and 75 of which were studied ultrastructurally. Results were analysed according to the mode of presentation of patients. Forty-one (35%) of the tumours were from patients with acromegaly or gigantism, ten (9%) from patients with Cushing's syndrome or Nelson's syndrome, 19 (16%) from patients with clinical features associated with hyperprolactinaemia and 48 (40%) from patients with space occupying lesions which appeared clinically to be overtly endocrinologically functionless. By light microscopy, using the immunoperoxidase (PAP) technique, immunoreactive GH was demonstrated in all the tumours from patients with acromegaly or gigantism, immunoreactive ACTH in all tumours from patients with Cushing's syndrome or Nelson's syndrome and immunoreactive PRL in 95% of tumours associated with effects of hyperprolactinaemia. Forty-five percent of the tumours from acromegalic patients contained some PRL-positive cells as well as GH-positive cells. Among the tumours which appeared clinically to be endocrinologically functionless were three tumours (from males) uniformly stained for immunoreactive PRL. Of the remainder, 60% were negative for immunoreactive hormones and 40% contained small numbers of cells which were positive for a variety of immunoreactive hormones. ACTH-cell and PRL-cell tumours had ultrastructural features as described in previous studies. Fifty percent of GH-cell tumours examined at the EM level contained fibrous bodies, while in the remainder these structures were not identified. Tumours with fibrous bodies were more likely to contain PRL as well as GH with immunoperoxidase. All tumours that were endocrinologically functionless and which were examined at the EM level contained secretory granules. Oncocytic change was common in these tumours. No ultrastructural differences were observed between those which contained immunoreactive hormones by light microscopy and those which did not.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 34 (1982), S. 382-390 
    ISSN: 1432-0827
    Keywords: Avian osteopetrosis ; Avian oncornavirus ; Ultrastructure ; Calcification ; Bone cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Diaphyseal tibial bone of 12.5 – 13-day and 19-day-old embryos and 20-day-old hatched chicks infected with retrovirus MAV.2-O were examined by transmission electron microscopy. The viruses were associated with lining osteoblasts and osteocytes. Whereas the infection of the osteoblast layer seemed to be a transient stage, virus association with osteocytes was a constant and main ultrastructural feature. The viruses were found either in the osteoid or in the periosteocytic space of the bone lacunae. They arose from dense cytoplasmic areas located near the cell plasmalemma via a budding process. The newly budded virus particles often had a large tail or a fine stalk-like process lost in the extracellular space. The viruses underwent calcification by deposition of inorganic material and were incorporated in the bone trabeculae. No production of virus was observed in typical osteoclasts with well-differentiated ruffled borders. The viral-induced avian osteopetrosis seemed to result from increased bone deposition through stimulation of osteoblast and osteocyte activities, whereas osteoclastic bone resorption seemed to be undisturbed.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-072X
    Keywords: Cyanobacteria ; Ultrastructure ; Nitrogen fixation ; Water stress ; Taxonomy ; DNA ; Plasmids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two strains of desiccation-tolerant coccoid cyanobacteria, Chroococcus S24, a marine form, and Chroococcus N41, a cryptoendolith isolated from a hot-desert rock, have been characterized. The mol % DNA base compositions of the strains are 47.1 and 48.9% respectively. Plasmid DNA was not detected in either strain. The pigment contents and nutritional characteristics of the strains are identical. Both lack phycoerythrinoid pigments and, in culture, behave as slow-growing halotolerant marine forms with elevated requirements for Na+, Cl−, Mg2+ and Ca2+. Sucrose was the only carbon source of those tested that supported photoheterotrophic growth. Each strain synthesizes nitrogenase under anaerobic conditions but not in air. Morphologically the two strains are indistinguishable. They are considered to be independent isolates of the same cyanobacterial species. Chroococcus N41 was studied in detail with the electron microscope. When brought to equilibrium at matric water potentials of-168 MPa and lower (to-673 MPa=c0.12a w) the protoplast shrinks, but the cells maintain the same size and diameter as those at-2,156 kPa (MN medium; control); the sheath expands and remains attached to the cell wall outer membrane by fibrils. The cell wall, cell membrane, thylakoid membranes, cyanophycin granules and carboxysomes appeared intact in desiccated cells.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 237 (1984), S. 357-362 
    ISSN: 1432-0878
    Keywords: Leydig-Sertoli cell interaction ; FSH stimulation ; Ultrastructure ; Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Interactions between Leydig and Sertoli cells, as well as a stimulatory effect of FSH on Leydig cell activity, have been reported in many studies. In order to investigate these interactions, the ultrastructure of immature pig Leydig cells under different culture conditions has been studied. When cultured alone in a chemically defined medium, there is a marked regression of the Leydig cell smooth endoplasmic reticulum and a swelling of the mitochondria. Addition of FSH or hCG does not prevent these phenomena. Co-culturing of Leydig cells with Sertoli cells from the same animal maintains the smooth endoplasmic reticulum at the level seen in vivo and in freshly isolated Leydig cells. The addition of FSH to the co-culture stimulates its development and increases Leydig cell activity, as assessed by an increase in hCG binding sites and an increased steroidogenic response to hCG. These results suggest that Sertoli cells exert a trophic effect on Leydig cells, and that the stimulatory effect of FSH on Leydig cell function is mediated via the Sertoli cells. These results reinforce the concept of a local regulatory control of Leydig cell steroidogenesis.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Fluorescence histochemistry ; Prevertebral ganglia ; Ageing ; 5-hydroxydopamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sympathetic post-ganglionic neurones in the coeliac-superior mesenteric ganglion (CSMG) complex of aged (24 month) rats have been studied by glyoxylic acid-induced fluorescence and electron microscopy. Comparisons have been made with the CSMG of young adult (4 month) rats. In the aged rats the noradrenaline fluorescence of the majority of neuronal perikarya was very low or absent and few intraganglionic fluorescent varicosities were seen. Lipofuscin pigment was very prominent at the nuclear pole region of neurones and also in dendrites and axonal processes. Ultrastructural studies revealed large accumulations of residual bodies at the nuclear poles and in axons and dendritic profiles. Within the perikarya many mitochondria were distorted or swollen, the rough endoplasmic reticulum was disarranged and much dilated as were Golgi cisternae. Primary lysosomes were encountered throughout the neurone perikaryon and its axonal or dendritic processes. In contrast to the young adult CSMG, no evidence for loading of transmitter storage vesicles with an identical dose level of 5-hydroxydopamine was detected in any part of the neurones of aged rats. This might reflect an impairment of the uptake mechanisms and/or storage of noradrenaline in aged sympathetic neurones and their axonal and dendritic processes.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-0878
    Keywords: Paraventricular neurones ; Alcian-blue labelling ; Ultrastructure ; Electrophysiology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural characterization of electrophysiologically identified neurones of the rat paraventricular hypothalamic nucleus was performed with extracellular labelling technique. The extracellularly recorded neurones are labelled with an electrophoretic deposit of alcian blue contained in the recording micropipette. The neurone thus labelled takes on a dark and shrunken appearance which enables its detection among neighbouring cells without, however, concealing its main morphological characteristics. 1) Spontaneously firing neurones, invaded by an antidromic action potential elicited by electrical stimulation of the neurohypophysis, were identified as magnocellular cells containing dense-cored vesicles of 200–250 nm in diameter. Dense-cored vesicles were not found in the antidromically activated neurones devoid of spontaneous activity. 2) Trans-synaptically activated neurones in the PVN or in its dorso-lateral edge were small cells devoid of dense secretory vesicles. 3) PV neurones in which neurohypophysial stimulation evoked no response, contained small, dense vesicles (100 nm in diameter) comparable with those found in parvocellular peptidergic neurones.
    Type of Medium: Electronic Resource
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