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  • Articles  (128)
  • Ultrastructure  (128)
  • 1975-1979  (128)
  • 1970-1974
  • 1978  (128)
  • 1
    ISSN: 1432-072X
    Keywords: Neurospora crassa ; Macroconidia ; Microcycle ; Heat ; Ultrastructure ; Nucleolus ; Proconidia ; Septa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Heat-shock of macroconidia of Neurospora crassa at 46°C followed by shift-down to 25°C determines premature conidiogenesis. The nuclei and cytoplasm of heat-treated, swollen conidia contain spots of a dense material especially concentrated around the nucleolus in short time treated ones. In the first proconidium apically budding on the enlarged tip of the premature conidiophore, small vesicles are peripherally spread. A few such vesicles are later seen lining the initially simple septum separating the proconidial units into conidia. The doubling of this interconidial septum is surface viewn as a thick annulus. Disarticulation of the conidial units intervenes along a septal furrow of electroluscent material. Interconidial continuity through the septal pores is transiently insured by a connective which is ruptured for final liberation of the conidia.
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  • 2
    ISSN: 1432-0738
    Keywords: Mercury ; Selenium ; Retention ; Liver ; Kidney ; Ultrastructure ; Interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Distribution and retention of mercury and selenium was studied in rats exposed repeatedly to HgCl2 injections (0.5 mg Hg/kg to the tail vein every other day) and intragastrically to Na2SeO3 (0.5 mg Se/kg every day), applying combined and separate administration of these metals for 2 weeks. Whole-body retention of mercury in the presence of selenium was augmented by 20% and that of selenium in the presence of mercury by 4% with respect to the administered dose. Combined administration of mercuric chloride and sodium selenite brought about damage to the epithelial cells of renal proximal convolutions and formation of protein casts in their lumen. These changes had the same pattern as those induced by administration of mercuric chloride alone, but the intensity was lower. Submicroscopic studies revealed that repeated combined administration of sodium selenite and mercuric chloride did not completely abolish the mercury-induced mitochondrial swelling and contributed to chromatin destruction in the hepatocyte nuclei.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 377 (1978), S. 157-174 
    ISSN: 1432-2307
    Keywords: Pancreatic diabetes ; Endocrine pancreas ; Islet composition ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The endocrine pancreatic tissue from patients with severe primary chronic pancreatitis (n=6), secondary chronic pancreatitis due to duct obstruction by carcinoma (n=6) and non-diabetic, non-pancreatitic controls (n=4) was studied qualitatively and quantitatively using specific immunocytochemistry and electron microscopy. Grouping of variously sized islets in the sclerotic tissue (sclerosis islets), islet neoformation by ductuloinsular proliferation, and intrainsular fibrosis were the main qualitative findings. Immunocytochemical quantitation of the distribution of insulin (B), glucagon (A), somatostatin (D) and pancreatic polypeptide (PP) producing cells revealed a significant relative increase in the number of A cells and a decrease in the number of B cells of the sclerosis islets in primary chronic pancreatitis (B-44.1±9.3%:A-38.3±2.4%:D-8.6±5.1%:PP-4.6±4.1%) as well as in secondary chronic pancreatitis (B-38.0±14.3%:A-38.4±19.0%:D-9.1±5.8%:PP-14.5±23.4%) compared with controls (B-71.1±8.1%:A-24.3±5.5%:D-8.0±2.8%:PP-0.5±0.4%). The number of PP cells was significantly increased in primary chronic pancreatitis only. It is suggested that scarring of the exocrine pancreas affects islet composition, probably by impairment of the local circulation and of glucose diffusion, thus leading to reduction of the number and glucose sensitivity of B cells. The hyperplasia of A and PP cells appears to be a secondary phenomenon due to the loss of B cells.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 378 (1978), S. 287-295 
    ISSN: 1432-2307
    Keywords: Giant cell tumor ; Ultrastructure ; Alkaline phosphatase ; Human bone neoplasias
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structural localization of nonspecific alkaline phosphatase was elucidated in two giant cell tumors of bone using lead as capturing ion and Β-glycerophosphate as substrate in the incubation solution. Lead phosphate precipitate — indicating presence of alkaline phosphatase — was demonstrated on the plasma membranes, and the membranes bordering vesicles and vacuoles of presumed endocytotic nature, in giant cells and type 1 stromal cells (fibroblast-like cells). The findings support the view that stromal cells type I and giant cells are histogenetically related.
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  • 5
    ISSN: 1432-2307
    Keywords: Pitutary ; Ultrastructure ; Vasopressin ; Prostaglandin ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ziel dieser Untersuchung war es, quantitative and qualitative Änderungen der ACTH-Zelle in der Rattenhypophyse nach Gabe eines spezifischen und eines unspezifischen Stimulus zu untersuchen. Es wurden ein CRF-Analogon (Lysin-Vasopressin) und ein Prostaglandin (Prostaglandin E1) benutzt. Jeweils 20 Ratten wurden für 4 Wochen Lysin-Vasopressin oder Prostaglandin E1 intraperitoneal injiziert. Die Hypophysen wurden licht- und elektronenoptisch sowie morphometrisch untersucht. Nach Gabe beider Stoffe konnte man eine Aktivierung der ACTH-Zellen beobachten. Die Vergrö\erung des Kerns, des Cytoplasmas und der an der Hormonherstellung beteiligten Zellorganellen lie\ sich morphometrisch nachweisen, wobei die Wirkung von Lysin-Vasopressin ausgeprÄgter war als die des Prostaglandins. Darüber hinaus konnte eine Zunahme der ACTH-Zellzahl gefunden und mit einem statistischen Test als signifikant nachgewiesen werden. Im Gegensatz zu Lysin-Vasopressin erstreckte sich die Wirkung des Prostaglandins auch auf andere Hypophysenzellen.
    Notes: Summary The aim of this study was to investigate the qualitative and quantitative changes of ACTH-cells in the rat after application of a specific and a non-specific stimulus. A CRF-analog (lysin-vasopressin) and a prostaglandin (prostaglandin E1) were used. 40 rats were injected lysin-vasopressin or prostaglandin E1, respectively, for 4 weeks. The pituitary glands were investigated by means of light microscopy, electron microscopy and morphometry. Activation of the ACTH-cells could be observed after use of both substances, the effect of lysin-vasopressin being more intense than that of prostaglandin E1. Enlargement of the nucleus, the cytoplasm and the organelles involved in hormone-production and -transport were found and verified by morphometry. Additionally an increase in number of the cells could be demonstrated. Prostaglandin influenced not only ACTH-cells, but also other cells of the anterior pituitary.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 379 (1978), S. 185-201 
    ISSN: 1432-2307
    Keywords: Giant cell tumor ; Ultrastructure ; Acid phosphatase ; Lysosomes ; Bone tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of the different cell types constituting a primary malignant giant cell tumor of bone has been studied and the localization of acid phosphatase in relation to the subcellular organelles been demonstrated. Three distinct cell types with characteristic ultrastructural features were observed: giant cells, fibroblast-like cells, and cells with abundant lipid inclusions and mitochondria. Certain differences were noted between these three cell types and their counterparts in benign giant cell tumors of bone (described in a separate report). The enzyme histochemical and morphological data suggested that the giant cells in the malignant tumor might possess a more active and expansive lysosomal apparatus than corresponding cells in the benign variant.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 379 (1978), S. 229-241 
    ISSN: 1432-2307
    Keywords: Placenta ; Ultrastructure ; Rhesus incompatibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electronoptical study has been made of eleven placentae from cases of materno-fetal rhesus incompatibility. The characteristic findings are focal, but sometimes quite extensive, syncytial necrosis, retention of normal pinocytotic and secretory activity in the non-necrotic syncytiotrophoblast, cytotrophoblastic hyperplasia, thickening of the trophoblastic basement membrane, immature-type endothelial cells in the fetal villous vessels and thickening or lamination of the capillary basement membranes. The pathogenesis of many of these changes is not clear but there is no evidence that they are immunologically mediated. It is suggested that the syncytial necrosis may be due to narrowing of the intervillous space as a result of increased villous size, that the cytotrophoblastic hyperplasia is a response to the syncytial damage and is responsible for the changes in the trophoblastic basement membrane and that the fetal capillary changes are indicative of endothelial cell damage due, possibly, to fetal anaemia. Despite the damage suffered by the placenta in materno-fetal rhesus incompatibility there is little evidence of impaired functional efficiency.
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  • 8
    ISSN: 1432-2307
    Keywords: Cerebellar astrocytoma ; Optic glioma ; Pilocytic astrocytoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural comparison of 8 cerebellar astrocytomas and 4 optic gliomas shows that the morphological patterns of both tumor-groups are identical. The confusion in nomenclature of these tumors is discussed and reasons for a preference for the term “pilocytic astrocytomas” are given. Further, pilocytic astrocytes seem to be a special, phylogenetically older, group of glial cells.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 378 (1978), S. 161-172 
    ISSN: 1432-2307
    Keywords: Chemodectoma ; Larynx ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present case report is concerned with a clinico-pathological study, including ultrastructural investigation, of a rare and uncommon laryngeal tumour, a chemodectoma, in a 62 year old patient. There have been 23 cases of laryngeal chemodectomas reported in the literature, and only three of them, including our own report, were investigated by electron microscopy. The tumours arise from the superior and inferior laryngeal nonchromaffin paraganglia or possibly from Kultschitzky-cells of the normal bronchial mucosa. Ultrastructurally they have all the characteristics of apudomas whose parent cells (the APUD-cells), usually show endocrine function and probably have their origin in the neural crest. The tumours show an aggressive type of behaviour, despite usually benign histological features when compared to chemodectomas at other sites in the head and neck region. Surgery is thus the therapy of choice.
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  • 10
    ISSN: 1432-2307
    Keywords: Thyroid ; Adenoma ; Ultrastructure ; Immunhistochemistry ; Thyroglobulin ; Lysosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Histological, immunhistochemical and electronmicroscopic studies of 12 human, scintigraphically “cold”, thyroid adenomas with specific cytological differentiation identified four different cell types: oxiphil cell, clear cell, ergastoplasm-rich cell and mitochondrion-rich cell. The oxiphil tumor cell can be recognized light-microscopically by its large size and its eosinophilic granular cytoplasm. Most of these cells do not produce thyroglobulin. The ultrastructural characteristics of oxyphil cells are principally mitochondria in great numbers and many large lysosomes. Clear cell adenomas show a trabecular growth pattern. The tumor cells have an abundance of cytoplasm which contains small acidophilic granules. Immunhistochemically we were able to demonstrate thyroglobulin in small amounts within cytoplasmic granules and more extensively within the follicle lumina. Electronmicroscopically we observed a large number of smooth surfaced vacuoles of varying size, extraordinary large lysosomes and occasional cisternae of rough endoplasmic reticulum, the latter probably corresponding to the immune-histochemically identified thyroglobulin granules. The ergastoplasm-rich-cell adenomas, which to the best of our knowledge have not been previously described, show a predominantly micro-to normofollicular architecture histologically without intrafollicular colloid. The cytoplasm of the ergastoplasm-rich cells reveales a strong positive thyroglobulin-staining reaction. The fine structure of these cells is characterized by the abundance of cisternae of the rough endoplasmic reticulum. The mitochondrion-rich-cell adenomas exhibited a microfollicular structure with an intensive acidophilic granular staining at the basal part of the tumor cells. Immunhistochemically and electronmicroscopically we found some morphologic and functional features which differentiate these cells from the oxyphil cell. Thyroglobulin was located predominantly in the apical portion of the cytoplasm in the mitochondrion-rich cells without sharp demarcation from the luminar thyroglobulin. Electron microscopically fewer basal and laterally located mitochondria were seen in mitochondrion-rich cells compared with oxyphil cells. As we could not find any sign of functional activity in the oxyphilic, clear cell and ergastoplasm-rich cell adenomas we analysed those aspects of the lysosomal system not concerned with the enzymatic digestion of thyroglobulin.
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  • 11
    ISSN: 1432-2307
    Keywords: Primary hyperparathyroidism ; Bone cells ; Bone matrix ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscope investigation has been carried out on needle biopsies of the iliac crest of 8 patients suffering from primary hyperparathyroidism. A marked increase in bone resorption was the most conspicuous finding. It was due both to increased osteoclastic activity and to periosteocytic osteolysis. The osteoclasts had a more strongly developed brush border and contained more cytoplasmic vacuoles than those in controls. Many osteocytes were found within enlarged, irregular lacunae, and were surrounded by a space containing amorphous, granular and filamentous material. Their mitochondria were sometimes calcified. Osteoblasts were more active than in controls as shown by the developed rough ergastoplasmic cysternae and thick osteoid borders found near some of them. The osteoid tissue, however, was uncalcified; ultrastructurally, lack of the calcification front and incomplete matrix calcification were demonstrable. Mast cells, and osteoclast- and macrophage-like giant cells were often found in the fibrotic marrow spaces. These results confirm that both the resorption and the formation of bone are stimulated in hyperparathyroidism. The calcification process is delayed and often remains incomplete.
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  • 12
    ISSN: 1432-2307
    Keywords: Pinguecula ; Pterygium ; Histology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two pingueculae combined with pterygia were studied by light and electron microscopy. Hyaline degeneration of the collagen, dark staining granular, von Kossa negative concretions and elastotic material were observed in both conditions together with marked changes in the fibroblasts, endothelial cells, pericytes and the basement membrane of conjunctival capillaries and small veins. The elastotic material is similar to that observed in solar elastosis, where the collagen fibers are less severely damaged. Chronic sun exposure of the pericorneal conjunctiva may damage endothelial cells primarily and disturb vascular exchanges. This would result in accelerated degeneration and regeneration of endothelial cells, in thickening of the basement membrane and, secondarily, disturbed metabolism of fibroblasts with alterations of the collagen and elastic fibers.
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  • 13
    ISSN: 1432-0533
    Keywords: Neuroblastoma ; Small-cell neoplasm ; Cerebral ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A small-cell neoplasm in the left temporal lobe of a 10 and a half year old boy was studied by light and electron microscopy. Routine sections of the mass showed a differentiating neuroblastoma with Homer Wright rosettes, several foci of immature neoplastic neurons (ganglion cells), many mitoses, arcas of necrosis and tumor vessels showing endothelial proliferation. Ultrastructurally, most cells resembled early fetal neuroblasts and also were similar to those in murine and peripheral human neuroblastomas.
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  • 14
    ISSN: 1432-0533
    Keywords: Irradiation edema ; Gravimetry ; Ultrastructure ; Vesicular transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Focal brain edema limited to one cerebral hemisphere was produced by ultraviolet irradiation of the exposed cortex. Tissue water content was determined by the gravimetric method which allows microsampling. Therefore, the spread of edema around the small necrotic area could be mapped more precisely than by determination of dry weight which calls for larger samples. As early as 30 min following irradiation, hyperemia and swelling of the brain are observed under the operating microscope. This correlates with venous stasis, hyperemia, and broadened perivascular spaces around venules and large capillaries accompanied by a marked rise in the specific weight of the tissue. After 4 h an edema front can be observed spreading from the perinecrotic zone in which there is a marked rise in endothelial cell vesicular activity. Edema reaches maximum levels in the deep white matter at 48 h post irradiation with normalisation of the tissue water content after 96 h. The velocity at which the edema front spreads from the cortex to the periventricular area lies in the range of 0.25 mm/h. Edema reabsorption coincides with signs of retrograde micropinocytosis in endothelial cells.
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  • 15
    ISSN: 1432-0533
    Keywords: Cultured ; Craniopharyngioma ; Typical ; Atypical ; Ultrastructure ; Electron microscopy ; Biochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Craniopharyngiomas are tumors of the suprasellar area, which are often cystic, encapsulated and slow-growing. Certain of these tumors can behave in an aggressive manner and either invade surrounding structures or recur. In order to determine characteristics which may aid in distinguishing typical from atypical lesions, a study of biopsy and tissue culture specimens from 25 human craniopharyngiomas was undertaken. Tissue culture observations reveal two distinct cell populations. Typical lesions grew in culture in an orderly epithelial pattern and had desmosome-tonofibril aggregates and smooth surface topography demonstrable by electron microscopy. In the atypical tumors the cell growth was irregular, with mitotic activity, cholesterol crystals and features characteristic of neoplastic transformation, such as surface microvilli, an increase of cytoplasmic basophilia, size and number of nucleoli and retraction of cytoplasm. Correlation with the clinical status of the patients suggests that tumors of the four patients which exhibited atypical features in culture behaved more aggressively.
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  • 16
    Electronic Resource
    Electronic Resource
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    Anatomy and embryology 154 (1978), S. 1-25 
    ISSN: 1432-0568
    Keywords: Bile canaliculus ; Development ; Glycogenesis ; Hepatocytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural changes during development and metamorphosis in the liver ofXenopus laevis have been investigated. In this species it was found that developmental processes, which ultimately lead to the formation of bile canaliculi, can be detected in the liver anlage as early as stage 35. While the wall of the primary liver cavity is thrown into folds which form the liver parenchyma, the bile canaliculi are formed (st. 36–38). Secretion into the lumen of the bile canaliculi was not found to occur before stage 47 and IDP-ase activity could not be detected in the bile canaliculi before stage 49. The intra- and extrahepatic portions of the hepatic duct system were found to be formed during the stages 40–41. The formation of the duct system involves cellular degeneration in the lumen of the future ducts. These processes are described in detail. The glycogen content of the developing hepatocytes received particular attention during the course of this study. It was found that after depletion of the embryonal glycogen the hepatocytes are completely free from glycogen during the stages 43–45. At stage 46, after the begin of feeding, beta as well as alpha particles of glycogen appear in the hepatocytes. These first reappearing glycogen particles are formed without the participation of SER membranes, in areas which are loaded with RNA particles. It was found that only after the synthesis of glycogen had been initiated SER membranes started to proliferate in the hepatocytes, where they were mostly found intermingled with glycogen particles. From stage 54 on, where the liver glycogen content was found to be 0.2%, the glycogen content of the liver almost continuously increased until it reached a temporary peak of 10% at the end of metamorphosis. These findings strongly contrast results reported for other amphibia, which at the end of metamorphosis have depleted their glycogen content completely. Details of the ultrastructural changes occuring during development of the hepatocytes, are also reported in this paper.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 154 (1978), S. 67-82 
    ISSN: 1432-0568
    Keywords: Urodeles ; Spinal cord ; Ependyma ; Glia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The structural organization of the ependymal and macroglial components of the central field of the spinal cord of postmetamorphic ribbed newts has been reinvestigated using elaborate fixation procedures for transmission electron microscopy. All along the central canal, the ependymal cells display ultrastructural features that strongly suggest a secretory activity. Infrequent mitotic images, occurring spontaneously among the ependymal cells, were observed. The tightly compacted periependymal stratum contains two types of glial cells: 1. oligodendrocytes, also observed outside this stratum as neuronal satellites, and 2. radial astrocytic cells, whose somata, exclusively located in the periependymal stratum, send their processes to the subpial lamina. The intercellular relationships between ependyma, oligodendrocytes and astrocytic cells are illustrated to show the continuity of the neuroepithelial configuration. Morphologic clues for identifying the cells of the central field of the urodele spinal cord are given. A gradient of differentiation of the oligodendroglial components could be postulated. In normal conditions, the astroglial differentiation is permanently arrested at the stage of radial glia. Some considerations concerning regeneration in the urodele spinal cord are submitted.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 154 (1978), S. 185-211 
    ISSN: 1432-0568
    Keywords: Adenohypophysis ; Cellular types ; Ultrastructure ; Birds ; Excalfactoria chinensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural analysis of the adenohypophysis in the male Chinese quail reveals seven different types of granular cells, and agranular folliculo-stellate cells. The cell types are assumed to be endocrine cells and are classified as: Type I cells (presumptive LH-gonadotrophs), with dilated endoplasmic reticulum, perinuclear spaces, and granules of 150–260 nm; Type II cells (presumptive FSH-gonadotrophs), with regularly-shaped cytoplasmic cisterns and small granules (80–150 nm); Type III cells (presumptive thyrotrophs), very close in appearance to the type II cells of normal birds; Type IV cells (presumptive prolactin cells), with very large secretory granules (up to 400 nm), Type V cells (presumptive corticotrophs), with abundant and electrondense granules (160–300 nm); Type VI cells, with irregularly-shaped granules; Type VII cells (presumptive somatotrophs), with abundant granules (130–220 nm) and less cytoplasmic structures. Cytological characteristics of the nucleus, and more particularly the presence of a Feulgen-positive nucleolus with a very particular ultrastructure are here reported. It is proposed that heterospecific associations of Chinese quail cells with chick cells can be used in embryological work for the study of cellular interactions.
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  • 19
    ISSN: 1432-041X
    Keywords: Liver ; Primary culture ; Ultrastructure ; Albumin synthesis ; Xenopus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscopic analysis of primary cultures derived from larvalXenopus liver has shown that these cells, although they form only two-dimensional aggregates, retain and presumably also develop structural characteristics typical of liver parenchyma cells, such as bile canaliculi with microvilli and epithelial junctional complexes. As judged from structural criteria, primary cultures contain 80–90% hepatocytes. In contrast to the intact tissue, primary cultures showed excessive development of microfilaments, however. Incorporation of labeled amino acids has revealed further that the capacity for protein synthesis is maintained in culture and that synthesis of liverspecific protein albumin is maintained in vitro, even in liver cultures derived from thyrostatic tadpoles. This latter result suggests that initiation of albumin synthesis in the larval liver is probably not dependent upon thyroid hormones but rather reflects the protodifferentiated state of this tissue.
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  • 20
    Electronic Resource
    Electronic Resource
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    Acta neuropathologica 41 (1978), S. 169-171 
    ISSN: 1432-0533
    Keywords: Pituitary gland ; Oncocytic adenoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cases of oncocytic adenoma occurring in the pituitary are reported. Both were men aged 40 and 50 years respectively and there was no evidence of endocrine abnormality. In both the tumours many cells showed abundant acidophilic finely granular cytoplasm which had not stained positively with PAS-orange G stain. Electron microscopically the cells contained numerous mitochondria associated with marked reduction of other cytoplasmic organelles including the secretory granules.
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  • 21
    ISSN: 1432-0533
    Keywords: Nemaline myopathy ; Neuromuscular junction ; Myotendinous junction-like structure ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Histological, histochemical and ultrastructural studies were performed on muscle biopsies from three siblings with congenital nemaline myopathy. Histological studies revealed type I fibre atrophy and type II fibre paucity. Ultrastructural studies of intramuscular nerves showed that the axonal diameters were very narrow compared with the width of myelin lamellae. Granular or membranous osmiophilic material occurred in the adaxonal Schwann cell cytoplasm and had a periodicity of 33–38Å. The neuromuscular junctions showed degenerative features such as glycogen granules or myelin figures in 27.1% of total terminal axons. The secondary synaptic clefts were markedly decreased in number and short in length. Myotendinous junction-like structures were found in 5.5% of the muscle fibres near the neuromuscular junctions, and often near sites of fibre-splitting. Rods in nemaline myopathy might be caused as a result of longitudinal splitting and disruption of fibres due to deficient regeneration of the muscle fibres associated with neurotrophic abnormalities.
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  • 22
    ISSN: 1432-0533
    Keywords: Tissue cultures ; Cytochalasin B and colchicine ; Cell motility ; Ultrastructure ; Glioma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Primary tissue cultures of human gliomas were treated with cytochalasin B (0.5–60 μg/ml for 90 min). Cell motility was inhibited irreversibly in glial tumour cells, but the effect was reversible on the mesenchymal cells growing in culture in the lower dose range. Cell adhesion was considerably reduced as the dose was increased, as was the capacity for cells to spread on a surface from suspension. Low concentrations of cytochalasin B caused negligible cell death and little disruption of cell ultrastructure. However, increases in dose were accompanied by a greater predominance of rough endoplasmic reticulum and inclusions and aggregation of microfilament bundles. As seen by scanning electron microscopy, cytochalasin B caused the withdrawal of peripheral cell borders, disappearance of ruffles and the breakdown of cytoplasmic lamellae. Charateristic surface blebs and folds appeared in their place. By comparison, colchicine (1–10 μg/ml) caused a less marked and non-specific reversible reduction in cell motility on both glial and mesenchymal cells. No significant change in cell adhesion or spreading took place even at high doses, although at all concentrations gross disruption of the cell surface took place with changes in ultrastructure characterised by loss of cytoplasmic microtubules and aggregation of 10 nm filaments.
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  • 23
    ISSN: 1432-069X
    Keywords: Colloid Milium ; Different types ; Histopathology ; Ultrastructure ; Colloid Milium ; Verschiedene Typen ; Histopathologie ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Unterschiede im Verlauf und Erbmuster des Colloid Milium deuten an, daß zwischen dem juvenilen und adulten Typ dieser Dermatose wesentliche Unterschiede bestehen. Ziel der vorliegenden Untersuchungen war, mit Hilfe von Licht-, Immunfluorescenz- und elektronenoptischen Methoden nach Unterschieden im mikroskopischen Bereich anhand je eines Falles zu suchen. Folgende Befunde wurden erhoben: Beim juvenilen Colloid Milium sind die Kolloidmassen nicht nur direkt unter dem Epithel abgelagert, sondern auch innerhalb der Epidermis häufig zu finden. Sie zeigen nach Kongorotfärbung einen Dichroismus und können Immunglobuline, Komplement und Fibrin enthalten. Elektronenmikroskopisch zeigt sich, daß sie aus dicht gepackten wellig verlaufenden Fibrillen bestehen, deren individueller Durchmesser etwa 80 Å beträgt. Innerhalb dieser fibrillären Massen sind häufig Melanosomen, Reste von Kernen und anderen Zellorganellen sowie Desmosomen nachweisbar. Beim adulten Colloid Milium sind die Kolloidmassen meist von der Epidermis durch einen Elastika-positiven Bindegewebsstreifen getrennt. Mit Kongorot sind sie nur schwach darstellbar und zeigen keinen Dichroismus. Fluorescenzoptisch zeigen sie eine bläuliche Autofluorescenz, aber keine spezifischen Ablagerungen. Elektronenmikroskopisch kann das adulte Kolloid als feingranuläres Material mit wenigen feinsten Mikrofibrillen charakterisiert werden, das in enger Nachbarschaft von Gefäßen mit verdichteter Basalmembran und von aktiven Fibroblasten gelegen ist. Auf Grund dieser Unterschiede können der juvenile und adulte Typ des Colloid Miliums klar auch mikroskopisch voneinander differenziert werden. Die Ergebnisse deuten darauf hin, daß beim juvenilen Typ vorwiegend epidermale Läsionen, beim adulten jedoch dermale Störungen eine wesentliche Rolle in der Pathogenese spielen.
    Notes: Summary Two different types of colloid milium are characterized on the basis of clinical and genetical parameters. In order to establish morphological criteria allowing a differentiation also at microscopic levels comparative histopathological, histo- and immunochemical as well as ultrastructural investigations were performed in a case of juvenile and a case of adult colloid milium. The following results were obtained: In juvenile colloid milium the colloid material is deposed in direct apposition to the basal epidermal layers and can be found also in suprabasal position within the epidermis. No actinic elastosis is present in the periphery of the deposits but they exhibit a green birefringency by investigation of Congo-red stained frozen sections in polarized light. Immunoglobulins, complement and fibrin can be demonstrated within the deposits by direct immunofluorescence. Electron microscopy reveales a fibrillar ultrastructure of the colloid masses, which contain numerous melanin granules and desmosomes. Therefore the colloid material in the juvenile type is most likely of epidermal origin. In adult colloid milium the colloid is usually separated from the epidermis by a band of connective tissue elements containing a considerable amount of elastin. The surrounding superficial dermis frequently exhibits elastotic changes. Congo-red reaction is only weakly positive and no dichroisms can be found. Direct immunofluorescence reveals no specific staining, but a blue autofluorescence of the material. Ultrastructurally, the adult colloid represents mainly finely granular material, with only few microfilaments. The masses are situated in the dermis, often near duplicated vascular basement membranes and in close apposition to active fibroblasts. Thus, the colloid material seems to be of dermal origin. The microscopic findings strongly indicate, that the two different types of colloid milium indeed represent different entities, discernable not only by clinical or genetic but also by histomorphologic parameters.
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  • 24
    ISSN: 1432-069X
    Keywords: Pseudolymphoma ; Oriental hornet venom ; Ultrastructure ; Pseudolymphoma ; Orientalische Wespe ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine einmalige sucutane Injektion des Giftes der orientalischen Wespe führt bei schwarzen Mäusen zu der Entwicklung eines subcutanen Knötchens, welches sich über 1 Jahr hält. Ultrastrukturell zeigt sich eine Anreicherung von Lymphocyten und Lymphoblasten und einige Plasmazellen mit Russelkörperchen. Zusätzlich werden einige Melanin enthaltende Makrophagen und auch solche mit aufgenommenen cellulären Abbauprodukten beobachtet. Die gesamte Reaktion wird mit anderen pseudolymphomatösen Reaktionen in der Haut in Beziehung gesetzt.
    Notes: Summary A single subcutaneous injection of Oriental hornet venom into black mice led to the development of a subcutaneous nodule which showed no change during the period of 1 year. Study of the ultrastructure revealed an accumulation of lymphocytes and lymphoblasts and a few plasma cells with formation of Russel bodies. In addition, a few melanin-containing macrophages and macrophages filled with cellular debris were found. This reaction is compared to other pseudolymphomatous reactions in the dermis.
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  • 25
    ISSN: 1432-069X
    Keywords: Nude mice ; Skin pigmentation ; Ultrastructure ; Tyrosinase activity ; Hair cycle ; Nackte Mäuse ; Hautpigmentierung ; Ultrastruktur ; Tyrosinaseaktivität ; Haarcyclus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Autoren untersuchten die Pigmentveränderungen an Haut und Haar an pigmentierten nackten Mäusen. Histologische und elektronenmikroskopische Untersuchungen und die Polyacrylamid-Elektrophorese der Tyrosinaseaktivitäten zeigten vom morphologischen und biochemischen, daß die Veränderungen der Programmierung solcher “nude” Mäuse auf den Haarcyclus und auf das Haarwachstum bezogen werden kann. In der Tat entwickeln sich die Haarfollikel cyclisch wie die der Mäuse mit normaler Haut. In depigmentierter Haut waren die Haare in der Ruhepause und es konnte keine lösliche Tyrosinase aufgefunden werden.
    Notes: Summary The authors have studied pigmentary changes of skin and hair due to the presence of the “nude” gene in pigmented species (C 57 Bl. 6J, C 3H). Morphological (histology, electron microscopy) and biochemical (polyacrylamide gel electrophoresis of tyrosinase activities) studies showed that the pigmentary alterations of the “nude” mice were related to the hair cycle and hair growth wave pattern. In fact, in the “nude” mice the hair follicles evolves cyclically similarly to mice of normal coat. In depigmented skin, the hair follicles were in the resting phase and no soluble tyrosinase could be demonstrated.
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  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 263 (1978), S. 159-169 
    ISSN: 1432-069X
    Keywords: Leiomyosarcoma of the skin ; Ultrastructure ; Cellular differentiation ; Accumulation of centrioles ; Cutanes Leiomyosarkom ; Ultrastruktur ; celluläre Differenzierung ; multiple Centriolen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine 61jährige Patientin hatte sich vor 15 Jahren einen Tumor vom linken Unterschenkel entfernen lassen. Im Bereich der Narbe kam es zu erneuter Tumorbildung. Die histologische Untersuchung zeigte einen aus meist spindeligen Zellen zusammengesetzten Tumor mit vielen Mitosen und Kernpolymorphie. Die Diagnose eines cutanen Leiomyosarkoms wurde durch den elektronenmikroskopischen Nachweis der für glatte Muskelzellen charakteristischen Zellelemente gesichert. Der Differenzierungsgrad der Tumorzellen variierte zwischen relativ differenzierten, filamentreichen Zellen, die noch an normale glatte Muskelzellen erinnerten, und ödematösen, filamentarmen, aber organellenreichen entdifferenzierten Zellen. Eine auffallende morphologische Besonderheit war der wiederholte Nachweis von zahlreichen akkumulierten Centriolen.
    Notes: Summary A 61-year old woman developed a tumourous nodule in her left leg. Fifteen years ago a similar tumour had been removed in the same localization. Histological examination performed on biopsy material showed bundles of predominantly fusiform tumour cells with nuclear pleomorphism and many mitotic figures. Electron microscopic examination confirmed the diagnosis of leiomyosarcoma by demonstration of the ultrastructural characteristics of smooth muscle cells. Cellular differentiation showed various degree ranging from smooth muscle cell type to dedifferentiated edematous tumour cells with scanty myofilaments. An important finding was the demonstration of multiple accumulated centrioles.
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  • 27
    ISSN: 1432-069X
    Keywords: Wound healing ; Collagen metabolism ; Collagen degradation ; Fibroblasts ; Ultrastructure ; Wundheilung ; Kollagenstoffwechsel ; Kollagenabbau ; Fibroblasten ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Kollagenstoffwechsel in granulierenden Hautwunden der Ratte wurde mittels biochemischer, tracerkinetischer und elektronenmikroskopischer Methoden untersucht. Die Ablagerung von Kollagen in Hautwunden der Ratte war nicht nur das Ergebnis eines Anstiegs der Kollagensynthese, sondern wurde ebenso durch eine Abnahme des Kollagenabbaus bedingt. Unsere Ergebnisse zeigten signifikante Unterschiede im Kollagenumsatz zu verschiedenen Zeiten der Wundheilung. Der herabgesetzte Kollagenkatabolismus in den frühen Stadien der Wundheilung steuerte in entscheidender Weise zur Kollagenakkumulation im Wundgebiet bei. Während späterer Stadien, zum Zeitpunkt der Wundkontraktion und der Remodellierung der Narbe, stieg die Umsatzrate des Kollagens an. Die dargestellten Ergebnisse werden im Zusammenhang mit den allgemeinen Kriterien der Narbenbildung diskutiert.
    Notes: Summary Collagen metabolism in granulating wounds of rat skin was studied with biochemical, isotopic and electron microscopical methods. Deposition of collagen in rat skin wounds was not only the result of an increase in collagen synthesis but it was also caused by a decrease in collagen degradation. Our investigations showed significant differences in the collagen turnover at different times of wound healing. Decreased collagen catabolism at the early stages of wound healing contributed decisively to collagen accumulation in the wound area. At later stages, during wound contraction and remodelling of the scar, the rate of collagen degradation rose. The above-mentioned results are discussed in the context of general criteria of scar formation.
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  • 28
    ISSN: 1432-0533
    Keywords: Dysplastic gangliocytoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of dysplastic gangliocytoma of the cerebellum, a rare disorder with unknown etiology and pathogenesis, was studied ultrastructurally. The intranuclear inclusions identified were not seen to be of viral origin. The ultrastructural characteristics of the abnormal cells support the prevailing theory that these cells represent hypertrophied granular neurons.
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  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 43 (1978), S. 153-159 
    ISSN: 1432-0533
    Keywords: Myelin ; Oligodendroglia ; Human pathology ; Ultrastructure ; Carbon monoxyde ; Anoxia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 24-year-old woman was found comatose after 2 days of cephalalgia and vomiting. An immediate diagnosis of carbon monoxyde poisoning was disclaimed when blood carbon monoxyde was found to be 1.75 ml/100. A diagnosis of acute intracranial hypertension led to trephination with ventricular punction and brain biopsy on the third day. The patient died on the eleventh day. Ultrastructural study of biopsy tissue showed nearly normal cortex, and injured white matter, with disrupted or destroyed myelin and pycnotic oligodendroglia in contrast with nearly normal axons, astrocytes, and capillaries. Autopsy showed a typical semioval center myelinopathy. After discussion of the histotoxic, vascular, and edema theories for myelinopathy pathogenesis, primary oligodendrogial lesion is considered, and correlated with the diphasic evolution often observed in the course of carbon monoxyde myelinopathy.
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  • 30
    ISSN: 1432-0533
    Keywords: Choroid plexus papilloma ; Ultrastructure ; Cytoplasmic ; Inclusions ; Silver bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three cases of choroid plexus papilloma were studied by light and electron microscopy. All had the typical papillary pattern, and, in addition, two exhibited solid areas of tumor growth which predominated in one case. PAS positive (diastase resistant) and argyrophilic cytoplasmic inclusions were present in all three tumors but were particularly abundant in the predominantly solid one. Ultrastructurally, the inclusions appeared as irregularly shaped structures containing lipid droplets, filamentous material and microtubules, and resembled the “silver bodies” of Biondi found in normal choroid plexus. Along with other ultrastructural features of normal choroid plexus, these cytoplasmic inclusions may be helpful in the differential diagnosis of papillary tumors involving the ventricular system.
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  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 44 (1978), S. 249-250 
    ISSN: 1432-0533
    Keywords: Organelle complex ; Ribosomes ; Meningioma (malignant) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural study of a malignant meningioma revealed an organelle complex composed of: (1) A band-like densification of the cell cytoplasm adjacent to and in contact with the cell membrane. (2) An arciform filament immediately subjacent to it, with concavity directed away from the cell membrane. (3) A row of regularly spaced ribosomes located in the concavity, but at some distance from the arciform filament. (4) A pericellular condensation of interstitial ground substance. Occasionally, a second, thinner filament was seen “threading” the ribosomes together. Its morphology was consistent with that described for messenger RNA. It is suggested that the ribosomes are engaged in the synthesis of proteins for other portions of the organelle complex and that the ultimate role of the specialized unit would be that of an attachment device.
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  • 32
    ISSN: 1432-0827
    Keywords: Shell formation ; Free nerve endings ; Ultrastructure ; Lymnaea stagnalis ; Biomphalaria pfeifferi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The mantle edge of the freshwater pulmonate snailsLymnaea stagnalis andBiomphalaria pfeifferi was investigated with histochemical and ultrastructural methods. The mantle edge gland, which is involved in shell formation, consists of the periostracal groove and the belt. This belt appears to be composed of various regions. In the area of the periostracal groove a number of subepithelial gland cell types occur; these release their products into the groove. Between the groove cells ciliated free nerve endings terminate; the corresponding perikarya occur in the subepidermal connective tissue. Also in the posterior belt region free nerve endings were observed between the epithelial cells; in addition, a particular type of subepithelial gland cell was found in this area. The epithelial cells of this part of the belt have the ultrastructural characteristics of ion and water transporting cells; they are probably involved in calcium deposition and resorption. The possible role of the free nerve endings and of the subepithelial gland cells is discussed.
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  • 33
    ISSN: 1432-0827
    Keywords: Bird egg shell ; Ultrastructure ; Calcification ; Electron diffraction ; Microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The egg-shell of Japanese quail was studied by several techniques. Semithin sections (1μm thick) of non-decalcified shell were observed by normal and polarized light microscopy. Thin sections of non-decalcified shell, examined by transmission electron microscopy, permitted us to observe the forms and dimensions of crystals of calcite within different layers of the shell: mammilary layer, layer of cones, palissade layer and surface crystal layer. There appears to be two distinct zones in the layer of cones as well as in the superficial crystal layer. Electron microdiffraction revealed the orientation of calcite crystals in the columns. Some crystal defects (twins?) were described and the possibility of their artefactual formation during ultramicrotomy is discussed. Localization of Ca, Mg, P and S were made by X-ray microanalysis of semithin sections. This technique shows that shell membranes, and chiefly the true cuticle, are also mineralized but, in these layers, minerals are not crystallized. Otherwise the distribution of Mg is not uniform throughout the shell thickness; it is less concentrated in the external zone of the layer of cones. These results together with observation of developing shells by scanning electron microscopy allowed us to propose a scheme for shell organization of the quail egg. This organization was related with decalcification which occurs during hatching.
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  • 34
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 118 (1978), S. 309-316 
    ISSN: 1432-072X
    Keywords: Streptomyces melanochromogenes ; Sporogenesis ; Formation of sporulation septum ; Delimitation, separation, and release of spores ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mode of spore differentiation in a strain of Streptomyces melanochromogenes was followed by analysis of ultrathin sections of sporulating aerial hyphae at various stages of sporogenesis. A special accent was laid on the formation of the sporulation septum and its alterations in the course of spore delimitation and separation. Distinct differences in formation and substructure have been observed between the cross walls of vegetative hyphae and the sporulation septa. Cross walls of vegetative hyphae are formed in a way typical for Gram-positive bacteria by a centripetal annular ingrowth of cytoplasmic membrane, on which wall material immediately is deposited. The development of the sporulation septa is characterized by the accumulation of amorphous material in addition to the newly synthesized wall layer inside the invaginating cytoplasmic membrane. This amorphous septal material will later be decomposed presumably by two lytic systems which cause the separation of the spores. The central region of the finished sporulation septum is perforated by microplasmodesmata. Spores are released by a break down of the surface sheath. The complete spores are enveloped by a twolayered cell wall and the spiny surface sheath.
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  • 35
    ISSN: 1432-069X
    Keywords: Chancroids ; Biopsies ; Haemophilus ducreyi ; Ultrastructure ; Ulcera mollia ; Biopsien ; Haemophilus ducreyi ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Anläßlich einer lokalen Häufung von insgesamt 26 Ulcus molle-Fällen in Berlin (West) wurden in Biopsien coccoide Stäbchen durch ultrastrukturelle Untersuchung entdeckt. Ihre Zellwand ist ca. 120 Å dick und trilaminar entsprechend Gram-negativen Bakterien. Die Bakterien sind hinsichtlich der Zellwandstruktur sowie der Cytoplasmazusammensetzung identisch mit Haemophilus ducreyi, die kulturell von typischen Ulcera mollia gezüchtet, intermittierend mikroskopisch auf Reinheit geprüft, in tierisches Material geimpft und anschließend ultrastrukturell untersucht wurden. In menschlichem ulcerösen Gewebe finden sich die Bakterien überwiegend im Extracellulärraum und in Gruppen gelagert.
    Notes: Summary During an endemic appearance of chancroids (26 cases) in Berlin (West) coccobacilli were disclosed in biopsies by electron microscopy. The bacteria were aggregated predominantly in groups in the extracellular space. Their cell wall is approximately 120 Å thick and trilaminar as in Gram-negative bacteria. Concerning the cell wall structure and the cytoplasmic composition, the detected coccobacilli are identical to culturally grown Haemophilus ducreyi obtained from chancroids.
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  • 36
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 117 (1978), S. 293-295 
    ISSN: 1432-072X
    Keywords: Rhodopseudomonas sphaeroides ; Intracytoplasmic membranes ; Membranes ; Ultrastructure ; Bacteriochlorophyll ; Chromatophores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The photosynthetic bacterium,Rhodopseudomonas sphaeroides, can be grown phototrophically (light, anaerobiosis), of chemotrophically (dark, aerobiosis). In the first case, it contains intracytoplasmic membranes with photosynthetic pigments. When shifted from phototrophy to chemotrophy these membranes disappear in an unknown fashion. In the present experiment, samples were taken for electron microscopy, cell density and bacteriochlorophyll determinations after shift from phototrophy to chemotrophy. The density of intracytoplasmic vesicles was measured on micrographs. During the first 2h growth is very slow and the ultrastructure remains unaltered. As growth resumes, the vesicles disappear at a rate which implies that they are not incorportated into the cytoplasmic membrane, nor actively digested, but remain intact and become increasingly diluted in the cytoplasm as the culture grows. The size of the vesicles was estimated to about 500 Å. The number of vesicles in phototrophically grown cells was calculated to about 575 per cell, and after 6h chemotrophic growth to about 100. The areas of the cytoplasmic and intracytoplasmic membranes are roughly calculated.
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  • 37
    ISSN: 1432-041X
    Keywords: Ultrastructure ; Scanning cytophotometry ; Chromatin ; Chondrocytes ; Regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les cellules cartilagineuses des membres postérieurs deTriturus cristatus en régénération après amputation, ont été étudiées en microscopie électronique et par cytophotométrie à balayage. Nous nous sommes intéressés à la structure et à la distribution de la chromatine mais aussi à différents organites cytoplasmiques. Dans l'étude de cytophotométrie à balayage, la chromatine a été considérée à travers son constituant majeur, l'ADN, coloré par la réaction de Feulgen. Au cours de la régénération du membre, l'hétérochromatine initialement condensée, essentiellement accolée à la membrane nucléaire se décondense. Les vacuoles du cytoplasme, caractéristiques des animaux âgés par rapport aux animaux jeunes, disparaissent, les mitochondries et le reticulum endoplasmique rugueux deviennent plus abondants. Les caractéristiques nucléaires de l'activation cellulaire apparaissent précocement, précédent les modifications cytoplasmiques et conduisent à des cellules en tous points identiques aux cellules d'animaux jeunes en dehors de tout processus régénératif. Cette phase d'euchromatisation et de restructuration cytoplasmique est peut-être nécessaire à l'accroissement d'activité métabolique et à la division cellulaire qui suivent. Son déroulement peut expliquer tout au moins le ralentissement de la régénération observé chez les animaux âgés par rapport aux animaux jeunes.
    Notes: Summary Cartilaginous cells of aged newts (Triturus cristatus) were studied during hind limb regeneration. The electron microscope was used to study the structure and distribution of chromatin in the cell nuclei, while the DNA content of the chromatin was measured by means of a scanning cytophotometer. Changes in the ultrastructure of the cytoplasm during regeneration were also studied. It was observed that the structure and distribution of chromatin in the activated cell is greatly modified. In the non-activated cell of the aged newt, the chromatin is found highly condensed and distributed peripherally close to the nuclear membrane. In contrast, in the activated cells, the chromatin is much less condensed and is distributed throughout the nucleus. Moreover, cytoplasmic vacuoles, found only in the non-activated aged cells, disappear and an increase in the mitochondria and rough endoplasmic reticulum is also observed. Changes in the nuclear structure are observed prior to the cytoplasmic modifications. It is interesting to note that the process of activation induces structural changes in the aged cells which make these cells appear to be structurally identical to the young cells. This process of rejuvenation takes 3–5 days in the newt. We suggest that these structural changes of the chromatin and cytoplasm in the aged cells are necessary to increase the metabolic activity which precedes cell division. It may also explain why regeneration takes a longer time in the aged animals than in the young ones.
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  • 38
    ISSN: 1432-069X
    Keywords: Mycobacterium marinum ; Ultrastructure ; High-turnover granuloma ; Immunogenic orgin ; Intracellular collagen precursor ; Mycobaterium marinum ; Ultrastruktur ; High-turnover Granulom ; Immunogenes Granulom ; Intracelluläre Kollagenpräcursoren
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Drei Knoten (klinisches Alter 3–5 Wochen) von 2 Patienten mit sogenannten Swimmingpool- oder Aquariumgranulomen wurden elektronenoptisch untersucht. Das cytohistologische Spektrum umfaßt sowohl akute exsudative, als auch chronische proliferative Entzündungszeichen. Bereits im 3 Wochen alten Granulom sind Epitheloidzellen und Kollagen produzierende Fibroblasten nachweisbar. Das Mycobacterium marinum-Granulom stellt gemäß dem cytologischen Aufbau ein sog. High-turnover Granulom mit allergischer Genese dar. Es entspricht damit mycobacteriellen Dermatosen bei bestehender guter Abwehrlage (Lupus vulgaris, tuberkuloide Lepra). In Abbau befindliche Mycobacterien konnten in wenigen Phagocyten entdeckt werden. Die Ultrastruktur des lebenden Erregers wird vergleichsweise von tierexperimentellem Material präsentiert. Geschwungene und ringförmige parallele Membranen (“Worm-like structures”) wurden im Cytoplasma von transformierten Makrophagen und in Fibroblasten beobachtet. Fadenförmige quergebänderte Strukturen (Periodizität 170–180 Å) im Lumen des rauhen endoplasmatischen Reticulums von einigen Fibroblasten werden als intracellulär aggregierte Kollagenpräcursoren interpretiert.
    Notes: Summary 3 biopsies of 3–5 week-old nodular lesions in 2 patients with socalled swimming-pool (aquarium-) granuloma have been examined by electron microscopy. The cytohistological spectrum simultaneously comprises acute exudative as well as chronic proliferative phenomena. Epithelioid cells and collagen producing fibroblasts already conspicious in 3 week-old granuloma. According to the cytological composition the Mycobacterium marinum granuloma represents a high-turnover granuloma with immunogenic origin. It is comparable to mycobacterial diseases in the presence of well developed cell mediated immunity (Lupus vulgaris, tuberculoid leprosy). Degrading mycobacteria have been rarely detected in phagocytes and are compared with viable bacilli in macrophages of experimentally infected mice. Curved and annular parallel membranes (“worm-like structures”) in the cytoplasm of transformed macrophages and in fibroblasts presumably originate from the membranes of endoplasmic reticulum. Cord-like structures with transverse bands (periodicity 170–180 Å) in the lumen of RER of some fibroblasts are interpreted as intracellularly aggregated collagen precursors.
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  • 39
    ISSN: 1434-4726
    Keywords: Cochlear spiral ganglion ; Ultrastructure ; Morphometry ; Influence of broad band noise ; Cochleare Spiralganglien ; Ultrastruktur ; Morphometrie ; Beschallung mit Breitbandrauschen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Nach 40minütiger Beschallung des Ohres mit Breitbandrauschen von 105 dB SPL waren bei den Ratten elektronenoptisch noch keine sicheren Veränderungen an den Spiralganglienzellen festzustellen. Erst ultrastrukturell-morphometrisch ließen sich statistisch signifikante Veränderungen des Chondrioms und der Organellen des Leistungsstoffwechsels bei den granulären Spiralganglienzellen nachweisen. Der Volumenanteil der Mitochondrien im Einheitsvolumen Zytoplasma nahm zu. Auch das Volumen und die Oberfläche des RER sowie das Volumen der freien Ribosomen und der Nucleolen vergrößerten sich im Einheitsvolumen Zytoplasma bzw. pro Zelle. Die physiologische Bedeutung dieser Veränderungen wurde diskutiert. Die Resultate zeigen u. a., daß Veränderungen der Cytoarchitektur in den granulären Spiralganglienzellen morphometrisch früher als elektronenoptisch registriert werden können.
    Notes: Summary The comparison of ultrastructural and ultrastructural-morphometric findings in spiral ganglion cells subsequent to broad band noise with 105 dB SPL over a period of 40 min demonstrates that there are morphometric changes of the cytoarchitecture of granular ganglion cells even without evident ultrastructural changes. Morphometric analyses shows a significant extention of the volume proportion of mitochondria per unit volume cytoplasm. The volume and the surface of the rough endoplasmic reticulum, the volume of the free ribosomes and the average single volume of the nucleoli increase per granular ganglion cell. The physiologic significance of these changes is discussed. The results show that changes of the cytoarchitecture of granular spiral ganglion cells are earlier detected by morphometry than by ultrastructural description.
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  • 40
    ISSN: 1432-1335
    Keywords: Hydantoin ; Malignant Lymphoma ; Mice ; Ultrastructure ; Hydantoin ; Maligne Lymphome ; Maus ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ultrastrukturelle Zellveränderungen werden beschrieben am Original-Tumorgewebe und an Tumorzellen aus der Kurzzeitkultur von malignen Lymphomen, induziert durch chronische Diphenylhydantoin-Exposition. Diese Tumoren entstanden in Mäuse-Inzuchtlinien mit niedriger (C57Bl) und hoher (SJL/J) spontaner Lymphomrate im fortgeschrittenen Alter, waren jedoch nicht induzierbar in einer Lymphom-resistenten Linie (C3Hf). Frühveränderungen des lymphoretikulären Gewebes bestanden in einer zunehmenden Atrophie des Thymus und der thymusabhängigen Partien, begleitet von einer diffusen retikulo-histiozytären Hyperplasie. Lymphome vom lymphoblastischen Typ entstanden im Thymus nach einer Latenzzeit von 4–8 Monaten mit nachfolgender Generalisation. Verschiedene atypische Veränderungen wurden an Tumorzellen beobachtet sowie das Auftreten von C-Typ-Partikeln in den Tumorzellkulturen und hinsichtlich der Pathogenese der Lymphome diskutiert.
    Notes: Summary Ultrastructural studies were done on cells from original tumors and from short time cultures of mouse thymic lymphomas experimentally induced by chronic exposure to diphenyl-hydantoin. The tumors appeared in mouse strains with low (C57Bl) and high (SJL/J) susceptibility to spontaneous lymphoma development and were not observed in a resistant strain (C3Hf). Thymic lymphoma development was usually preceded by increasing lymphoreticular atrophy followed by progressive reticulohistiocytic hyperplasia, and subsequently spread to other tissues. Morphologically the tumor was characterized as a lymphoblastic lymphoma. Abnormal cell changes in the original tumors and cultured cells, and the presence of murine C-type particles in the cultured cells but not in the original tumors, are discused in relation with the disturbance of immune system and the lymphoma enhancement produced by diphenyl-hydantoin.
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  • 41
    ISSN: 1432-1335
    Keywords: Clear cells ; Salivary gland tumors ; Ultrastructure ; Differential diagnosis ; Helle Zellen ; Speicheldrüsentumoren ; Ultrastruktur ; Differentialdiagnose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zu den hellzelligen Speicheldrüsentumoren gehören monomorphe hellzellige Adenome, hellzellige Carcinome, hellzellige Varianten der Acinus- und Mucoepidermoidtumoren, Talgdrüsentumoren, Speichelgang-Carcinome und pleomorphe Adenome mit hellzelligen Abschnitten. Der lichtmikroskopische, deskriptive Begriff der hellen Zelle umfaßt bei einer weiteren cytochemischen und elektronenmikroskopischen Analyse Zellformen unterschiedlicher Herkunft und funktioneller Bedeutung. Folgende Zelltypen wurden näher analysiert: indifferente Gangzellen (geringe Organellenausbildung, Desmosomen), speichernde Streifenstückzellen (Glykogengranula, zahlreiche Mitochondrien, basales Labyrinth), Myoepithelzellen (Myofilamente, Pinocytose-Vesicel, Lipofuscingranula, Hemidesmosomen), epidermoide Zellen (Tonofilamente, Desmosomen), Becherzellen (Schleimvacuolen, basales endoplasmatisches Reticulum), Talgdrüsenzellen (Lipidtropfen, Mikrovilli, Desmosomen) und helle Acinuszellen (elektronenoptisch helle Sekretgranula, kleine Mitochondrien, kleiner Golgiapparat). In die Differentialdiagnose müssen auch hellzellige Tumorformen der Speicheldrüsenregion einbezogen werden, welche primär nicht vom Speicheldrüsengewebe ausgehen. Hierzu gehören Metastasen hypernephroider Nieren-Carcinome, Paragangliome, Glomustumoren Masson, Granularzelltumoren und alveoläre Weichteilsarkome.
    Notes: Summary Clear cell tumors of the salivary glands are monomorphic clear cell adenomas, clear cell carcinomas, clear cell variants of acinic cell and mucoepidermoid tumours, sebaceous cell tumors, salivary duct carcinomas and pleomorphic adenomas with clear cell sectors. At the light microscopical level the descriptive term of the clear cell comprises cell types of different origin and functional importance which can be differentiated by cytochemistry and electron microscopy. The following cell types were analysed precisely: indifferent duct cells (small formation of organelles, desmosomes), storing striated duct cells (glycogen granules, multiple mitochondrias, basal labyrinth), myoepithelial cells (myofilaments, pinocytosis vesicles, lipofuscin granules, hemidesmosomes), goblet cells (mucous vacuoles, basal endoplasmatic reticulum), sebaceous cells (lipid droplets, microvilli, desmosomes) and clear acinic cells (electron pale secretory granules, small mitochondrias, small golgi apparatus). Clear cell tumor types of the salivary gland region which primarely do not derive from the salivary gland tissue must also be included in the differential diagnoses. These are metastases of hypernephroid renal carcinomas, paragangliomas, glomus tumors of Masson, granular cell tumor and alveolar soft-part sarcomas.
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  • 42
    ISSN: 1432-0878
    Keywords: Subfornical organ ; Circumventricular organ ; Coturnix quail ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of the subfornical organ (SFO) of the Japanese quail has been studied by light and electron microscopy. The SFO is a small semiglobular bulge in the midline on the rostrodorsal wall of the third ventricle between the anterior commissure and tela choroidea. The organ consists of three main parts, anterior stalk, the corpus and the posterior stalk. The anterior stalk is covered by ependymal cells with a few cilia, but the corpus and posterior stalk are characterized by a distinctive lack of cilia and by flat or bulging cell surfaces, which have the appearance of cobble stones. The large bulbous protrusions in the ependymal surface of the posterior stalk suggest a secretory function into the ventricle. In the subependymal layer, there are a few parvocellular neurons that contain small mitochondria, moderately developed Golgi apparatus, lysosomes, dilated cisternae of rER and a few dense-cored granules of 100–120 nm in diameter. They appear to be secretory in nature. Two types of glial cells occur in the subependymal and internal layers. One is small and spindle-shaped with a dense nucleus and elongated cytoplasmic processes; it may be microglial. The other is a small polygonal cell with rounded nucleus and clear cytoplasm containing bundles of filaments; it may be a protoplasmic astrocyte. The neuropil contains three types of axons. The first contains dense-cored granules, 80 nm in diameter, and clear vesicles, 40–60 nm in diameter and is involved in axosomatic synapses. The second type contains dense granules, 120 nm in diameter, and clear vesicles, 40–80 nm in diameter, and shows axodendritic synapses. The third contains peptidergic granules about 100–120 nm in diameter and seems to belong to the organ-specific nerve cells. These axons terminate at the perivascular space of the blood capillaries, suggesting secretion into the blood.
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  • 43
    ISSN: 1432-0878
    Keywords: Area postrema ; 6-Hydroxydopamine ; Degenerative changes ; Ultrastructure ; Cynomolgus and squirrel monkeys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 6-Hydroxydopamine (6-OH-DA) has been shown to produce degenerative changes in noradrenergic nerve terminals and preterminals in the CNS following intracisternal, intraventricular or direct injection into the brain parenchyma. Systemic injection of 6-OH-DA is known to result in degenerative changes in noradrenergic terminals in the peripheral nervous system. However, only a few studies have been carried out on the effects of systemic injections of 6 OH-DA on noradrenergic terminals in the CNS. In the present study cynomolgus and squirrel monkeys were injected intravenously on two successive days with total doses of 350mg/kg and 150 mg/kg of 6-OH-DA, respectively, and sacrificed at 2 and 24 h following the second injection. Degenerative changes in the area postrema (AP) neurons in all injected animals were characterized by a generalized increase in electron density of cytoplasmic elements in axonal terminals and preterminals. Multilamellar bodies, clusters of clear and dense core vesicles, increased numbers of secondary lysosomes, and an increase in the number of glycogen granules were observed in these structures. In astrocytes the amount of glycogen increased markedly in injected animals, but no other glial alterations were observed. The number of mast cells in the AP was greater in injected than in noninjected animals, both in the perivascular spaces (PVS) and in parenchymal locations. Cell processes in the PVS were occasionally observed to contain electron dense bodies, and degenerative changes were seen in supraependymal processes in some injected animals.
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  • 44
    ISSN: 1432-0878
    Keywords: Osteodentine ; Anarhichas lupus ; Ultrastructure ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Le tissu dentinaire d'Anarhichas lupus s'est révélé être une ostéodentine vasculaire. Les études en MET, MEB et diffraction X montrent l'hétérogénéité de ce tissu. L'aspect désordonné des fibres de collagène, incomplètement minéralisées (leur striation est encore bien visible), explique la complexité de la répartition des cristaux puisqu' elles en déterminent l'ordonnance. La minéralisation imparfaite du tissu, dont témoignait déjà la striation visible du collagène, est confirmée par l'analyse des poudres en diffraction X (la cristallinité de l'ostéodentine vasculaire est nettement inférieure à celle de la couche de tissu dentaire périphérique) et par l'examen en MET de haute résolution, aucun réseau cristallin n'ayant pu être mis en évidence. L'ostéodentine, l'os basal et l'os profond ont en commun une phase minérale, avec une organisation plus ou moins bonne, différente du système des apatites.
    Notes: Summary TEM, SEM and X-ray diffraction analysis demonstrate the heterogeneity of the dentinal tissue of Anarhichas lupus, a vascular osteodentine. The disordered aspect of collagen fibres, incompletely mineralized (the periodical striation being still visible), explains the scattered distribution of crystallites since they are responsible for their arrangement. The low degree of mineralization revealed by the visible collagen striation is confirmed by X-ray diffraction analysis (the crystallinity of vascular osteodentine being much lower than that of the peripheral dental tissue) as well as by high resolution TEM, since no lattice planes could be observed. Osteodentine, supporting bone and proper bone have in common a mineral phase, more or less organized, different from the apatite system.
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  • 45
    ISSN: 1432-0878
    Keywords: Pineal organ, rat ; Ultrastructure ; Gonadotropic hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The influence of gonadotropic hormones on the ultrastructure of rat pinealocytes was studied. Human chorionic gonadotropin (HCG) as well as pregnant mare serum gonadotropin (PMSG) caused a marked activation of pinealocytes. It is characterised by a conspicuous proliferation of the granular endoplasmic reticulum and Golgi apparatus as well as an increase in number of dense core vesicles, mitochondria, dense bodies, subsurface cisternae and vesicles in the terminal buds of pinealocyte processes. The changes after HCG administration were more pronounced than after PMSG.
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  • 46
    ISSN: 1432-0878
    Keywords: Myocardium ; Mouse ; Ultrastructure ; Leptofibrils ; Desmosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The papillary muscle of the heart of adult white mice is investigated. Intrafibrillarly located leptomeric fibrils, frequently encountered in the Z-band region of the myofibrils. The leptomeric fibrils are always running in a transverse direction and often in close proximity to the transverse tubules (which are also located at this level). There seems to be a close connection between the dense striae of the leptofibrils and the Z-bands of ordinary myofibrils. The leptomeric fibrils are spindle-shaped and have a length varying between 0.6 and 1.2 μm. The banding periodicity of the fibrils is approximately 0.16 μm. Occasionally desmosomes are observed in the T-tubule system.
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  • 47
    ISSN: 1432-0878
    Keywords: Neural lobe of hypophysis ; Hibernating mammals ; Ultrastructure ; Neurosecretory granules ; Whorls
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'ultrastructure de la posthypophyse du Lérot a été examinée à différents stades du cycle annuel de ce rongeur hibernant. Il n'a pas été observé de différences évidentes entre les stades étudiés, et sont donc présentées ici les caractéristiques générales retrouvées chez tous les animaux. Les axones neurosécréteurs et leurs terminaisons peuvent être divisés en deux catégories suivant l'aspect des grains de neurosécrétat et des microvésicules présents. Le premier type contient des grains arrondis, à contenu d'apparence homogène, avec des microvésicules rondes. Dans les autres axones, les grains sont de forme variable, souvent allongés, et leur contenu présente deux sortes d'organisations cristallines; les microvésicules y sont en majorité aplaties. Considérant comme improbable que cette dualité résulte seulement d'un artefact, trois hypothèses sont envisagées. La dualité d'aspect des grains peut être liée à leur contenu en hormone (ocytocine ou vasopressine); ou bien l'aspect des grains peut correspondre à leur degré de maturation. Il est possible aussi que ces explications soient toutes deux valables. Par ailleurs, les pituicytes du Lérot contiennent fréquemment un réticulum endoplasmique organisé en lamelles concentriques (whorls). La signification de ces formations reste pour l'instant obscure.
    Notes: Summary Ultrastructural examination of the posterior pituitary of the garden dormouse (Eliomys quercinus L.) was carried out at different times in the annual cycle of this hibernating rodent. Obvious differences between experimental groups have not been observed, and the results presented here must be considered as general features of the garden dormouse posterior pituitary. Neurosecretory axons and endings can be divided into two types, according to different aspects of neurosecretory granules (NSG) and microvesicles (MV). One type contains spherical NSG with homogeneous cores and round MV. In the other type, NSG have various, often elongated, shapes. Their content shows two types of crystalline structures and most of the MV have flattened aspects. As it is very unlikely that this duality in NSG is a result of an artefact of fixation, three hypotheses are presented as explanation. The duality of NSG might be related either to their hormonal content (oxytocin or vasopressin) or to their degree of maturation. Moreover, both explanations may be valid. In the species studied, pituicytes often contain concentric lamellar structures of the endoplasmic reticulum (whorls), the significance of which remains obscure.
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  • 48
    ISSN: 1432-0878
    Keywords: Cuticle ; Epidermis ; Chironomus ; Respiration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The larval integument of the midge, Chironomus riparius Mg., is unusually thin although it conforms with the normal insect pattern. The cuticle of the post-cephalic segments is about 3 μm thick and overlies an epidermis which has an irregular basal plasma membrane resulting in spaces occurring between it and the basement membrane. The ventral tubuli have a similar epidermis but the cuticle is somewhat thinner. The anal papillae have the thinnest cuticular covering with a uniquely folded epicuticle of variable thickness, and their epidermis has the characteristics of a transporting epithelium. No evidence of pore canals could be found in the cuticle of any part except the head capsule which has a remarkably smooth epicuticle and a distinct layer which may represent the exocuticle. There are no spaces between the basement membrane and basal plasma membrane of the epidermis in the head. Ultrastructural evidence would suggest that gaseous exchange can occur across most of the post-cephalic integument.
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  • 49
    ISSN: 1432-0878
    Keywords: Photoreceptors ; Arthropod ; Spider (Argiope amoena) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The anterolateral eye, the posterolateral eye and the posteromedial eye of the web-building spider, Argiope amoena have been examined by light and electron microscopy. The dioptric apparatus of all three eyes is similar in structure, and consists of a cornea, a lens and a vitreous body. The retina contains monopolar receptor cells, the cell bodies of which are present beneath the vitreous body in all three eyes. Proximal processes of the receptor cells form rhabdoms beneath the cell body layer and then extend toward the first optic glomerulus as an ocellar nerve. Two distinct patterns of retinal organization are present in the three eyes. In one type the rhabdomic layer of the retina is backed by a pigmented layer. In the other type the rhabdomic layer is backed by a tapetal reflecting layer. Rhabdomic structure and cytoplasmic inclusions of the receptor cells differ greatly between the two types. The anterolateral eye possesses a single type of retina with the rhabdoms backed by the tapetum. Both the posterolateral and the posteromedial eye are similar in structure, each possessing beneath the common dioptric apparatus retinae of both types.
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  • 50
    ISSN: 1432-0878
    Keywords: Fat body ; Aedes aegypti ; Vitellogenin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the fat body of Aedes aegypti was followed from emergence through a blood meal. Changes in the volume of protein granules and lipid droplets were also examined. The relationship of these events to the known endocrinology of vitellogenin synthesis in mosquitoes is discussed.
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  • 51
    ISSN: 1432-0878
    Keywords: Lung ; Amphibia ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural and morphometric investigations were performed on the lung of the European salamander, Salamandra salamandra L. Folds of first and second order are covered with a ciliated epithelium containing goblet cells. The respiratory surface of the lung is lined by a single type of cell which, in amphibians, combines features of type I and type II alveolar cells of the mammalian lung. In the salamander the respiratory and ciliated epithelial cells as well as goblet cells possess electron dense and lucent vesicles in their cytoplasm as well as lamellar bodies. A small amount of surfactant, composed most probably of phospholipids and mucopolysaccharides, was observed covering the entire inner surface of the lung. Morphometric methods were used to determine the dimensions of the perinuclear region of pneumocytes, the thickness of the air-blood barrier and lung wall, and also the diameter of capillaries. The thickness of the respiratory air-blood barrier was found to be considerably higher than that of the corresponding barrier in mammals.
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  • 52
    ISSN: 1432-0878
    Keywords: Leydig cells ; Seminal vesicle ; Pineal gland ; Golden hamster ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fine structural changes of testicular interstitial cells of Leydig and secretory cells of seminal vesicles were studied in golden hamsters under different functional states of the pineal gland. Experiments were performed in the reproductive season (summer months). In the hamsters blinded for 8 weeks the testes and the seminal vesicles were markedly atrophic, and the Leydig cells and the secretory cells of seminal vesicles were extremely involuted. By contrast, both types of cells in the pinealectomized or superior cervical ganglionectomized hamsters exhibited cytological features suggestive of an enhanced secretory activity. This study shows that functional activity of Leydig cells as well as secretory cells of seminal vesicles in the hamster may be depressed or augmented by stimulating or inhibiting the pineal antigonadal function, respectively, without performing hypophysectomy or hormonal administration.
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  • 53
    ISSN: 1432-0878
    Keywords: Crustacean hemocytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A fine structural analysis of hemocytes recovered from the pericardial sinus of the blue crab (Callinectes sapidus) demonstrates that hyaline cells, intermediate cells, and granuloyctes are present in the hemolymph. A detailed consideration of their shared and differing cytological features suggests that the various blood cells represent different stages of cytogenesis along a common or single path of cellular differentiation. The potential functional complexity of the hemocytes is attested to by the occurrence within their cytoplasm of three and/or possibly four morphologically distinct types of inclusion bodies, and other membrane-bounded compartments (e.g., lysosome-like structures, autophagic vacuoles, peroxisome-like bodies) whose function is unknown. Preliminary examination of the well-developed Golgi organelle in the intermediate cells and granulocytes indicates its probable participation in the elaboration of the inclusion bodies; however, the details of its role in granulogenesis and in the known plurifunctional capacities of these cells remain obscure.
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  • 54
    ISSN: 1432-0878
    Keywords: Fat body ; Cockroach ; Reproductive cycle ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The central fat body of the ovoviviparous cockroach Nauphoeta cinerea was studied during the first reproductive cycle of the female by means of light microscopy, autoradiography and electron microscopy. Comparative studies in larval stages were also undertaken. The fat body of Nauphoeta contains a large amount of lipid droplets and the remaining cytoplasm is very scarce. The cytological cyclicity of the fat body is consistent with the known biochemical rhythms of vitellogenin production. The proteosynthetic apparatus appears about 3 days after imaginal ecdysis, along with vitellogenin. The ribosomal endoplasmic reticulum (RER) shows a tremendous increase by the 7th day of the first cycle. The most active period of vitellogenin production lasts from day 7 to day 12. The proteosynthetic apparatus then returns to an inactive stage and disappears. This inactive condition lasts to the end of the gestation period. The autoradiographic results are consistent with the cytological features.
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  • 55
    ISSN: 1432-0878
    Keywords: Planarian ; Scanning electron microscopy ; Epidermis ; Sense organs ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epidermis of D. tigrina was examined using the scanning electron microscope. Both dorsal and ventral surfaces are extremely irregular in contour, as well as being permeated by large numbers of pores. Cilia are restricted to the ventral surface, the auricles and that part of the dorsum adjacent to the auricles. Club-shaped receptors, as well as cilia, were seen in the auricles. The epidermis anteriad to the eyespots is indistinguishable from that covering the remainder of the dorsal surface. Light rays could not enter the eyespot through this rough epidermal surface without becoming diffracted in an irregular fashion. It was therefore concluded that visual image perception is not a function of the planarian eyespot.
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  • 56
    ISSN: 1432-0878
    Keywords: Insect-reproduction ; Ovary ; Oviduct ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lateral oviduct and calyx of nulliparous Aedes aegypti on a sucrose diet are both flattened sacs, lacking a well defined lumen. Both are formed of an inner epithelial and an outer muscular layer, each one cell thick. The lateral oviduct is surrounded by a circular muscle sheath which is continuous with the ovarian sheath. Each ovariolar sheath is continuous with the outer layer of the calyx. The structure of both the lateral oviduct and the calyx is greatly modified after the initial blood meal. A distinct lumen develops; there is an extensive development of the outer muscular layers, and the inner epithelial layers become invaginated forming deep crypts lined with extensive microvilli. The follicular stem, which joins the primary follicle to the calyx in each ovariole, is not hollow and does not mark the opening into the calyx through which the mature egg can pass. The eggs gain access to the oviductal system after the calyx extends around the follicular epithelium of the primary follicle, when breaks appear in the calyx wall opposed to the follicular epithelium, until the mature eggs, eventually lie in a highly distended thin-walled sac of calyx from which they have direct and easy access to the lateral oviduct. After oviposition, this sac contracts to occupy once more a compact axial position in the ovary. Remnants of the follicular epithelium, containing many lysosomes are attached to the calyx at this time.
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  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 194 (1978), S. 125-130 
    ISSN: 1432-0878
    Keywords: Sarcotubular development ; Chick embryo ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dilations of the sarcotubular system and misaligned myofilaments have been reported as early indicators of muscular dystrophy in skeletal muscle. Since the developing tubular component is believed instrumental in initial myofilament alignment during myogenesis, tubular development is evaluated using normal and dystrophic chick embryo skeletal muscle and cultures of normal and dystrophic embryonic pectoral muscle incubated in the presence of horse spleen ferritin. Comparisons of the findings show that periodic tubules are absent from dystrophic somitic muscle and that invaginating tubules from the sarcolemma are found in fewer, randomly located areas of dystrophic pectoral muscle cells. The results indicate that the tubular component is not involved in the bizarre vesiculations seen in mature dystrophic muscle, however, the malalignment of dystrophic myofilaments is probably the result of the poorer development of the T system in this muscle.
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  • 58
    ISSN: 1432-0878
    Keywords: Tubule aggregations ; Granular endoplasmic reticulum ; Gastropoda ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Aggregations of cylindriform tubules closely packed in a hexagonal arrangement and associated with the rough-surfaced endoplasmic reticulum (RER) are described in cells of the digestive gland of a sacoglossan gastropod. Each tubule is approximately 61 nm in outer diameter and the central lumen is lined with a layer of finely granular material. The tubule wall is composed of approximately 22 dense subunits. Adjacent tubules are associated with a pair of indistinct granules. Membranes of the RER frequently join the aggregations. The lumen of a tubule may be continuous either with the intracisternal space of the RER or with the cytoplasmic matrix of the cell. It is suggested that the aggregations of tubules are elaborations of the endoplasmic reticulum.
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  • 59
    ISSN: 1432-0878
    Keywords: Periderm granules ; Regenerating feather ; Ultrastructure ; Jungle fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Periderm granules in the support cells of regenerating feathers of mature male Jungle Fowls were studied ultrastructurally and histochemically. Histochemical results showed the absence of carbohydrate and lipid, and the presence of protein in the periderm granules. The periderm granules were measured at successive levels of feather regeneration. The mean size of the periderm granules increased significantly as the regenerating feather matured, and this observation was suggestive of a storage function, perhaps of surplus or waste protein. The cells in which the periderm granules are found also contain glycogen. There are numerous desmosomal junctions on their interdigitating plasma membranes. These transient cells may collect waste, provide nutrition, and serve as a protective barrier for the definitive cells of the regenerating feather.
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  • 60
    ISSN: 1432-0878
    Keywords: Spermatids ; Human ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osmiophilic granules with surrounding vesicles resembling flower-like structures occur transiently during the differentiation of human spermatids. These organelles are incorporated into the residual bodies when mature spermatids are released from the germinal epithelium.
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  • 61