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  • 2015-2019
  • 1995-1999  (62)
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  • 2015-2019
  • 1995-1999  (62)
  • 1975-1979  (458)
  • 1935-1939
  • 1925-1929
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  • 1
    Digitale Medien
    Digitale Medien
    Infraterminal spreading and extrajunctional expression of nicotinic acetylcholine receptors in denervated rat skeletal muscle (1999)
    Springer
    Experimental brain research 125 (1999), S. 426-434 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Key words Acetylcholine receptor ; Nicotinic ; Denervation supersensitivity ; Neuromuscular junction ; α-Bungarotoxin ; Immunocytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Through the use of biotinylated-bungarotoxin and monoclonal antibodies, the nicotinic acetylcholine receptor (nAChR) was localized in the subneural apparatus of mammalian motor end plates of the flexor digitorum brevis muscle of the adult rat at the light and electron microscopic levels. Under normal conditions, nAChR was located in the primary post-synaptic membrane of the neuromuscular junction, and the depths of the junctional folds constituting the secondary post-synaptic membrane did not contain any nAChR. Up to 75 days after repeated transection of the related motor nerve (sciatic), there was no major alteration in the light-microscopic localization of junctional nAChR in the subneural apparatus, except for a moderate shrinkage and increased immunocytochemical reactivity of the subneural apparatus. At the electron microscopic level, however, immunocytochemical reactivity gradually occupied the entire extent of the secondary post-synaptic membrane, including the depths of the junctional folds, which exhibited extensive branching. In non-innervated portions of the muscle fibers, nAChR receptor appeared in a linear localization on the surfaces of denervated muscle fibers. This linear reaction was not continuous with the nAChR reaction of the motor end plates. It is concluded that denervation supersensitivity might not be due to spreading of junctional nAChR from the end-plate area, but rather to expression of nAChR in non-innervated portions of the muscle fiber and to the infraterminal (subsynaptic) spreading of nAChR into the depths of junctional folds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002210050699
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  • 2
    Digitale Medien
    Digitale Medien
    Electron microscopic and immunohistochemical studies of gastrointestinal stromal tumors (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 213-220 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words Gastrointestinal stromal tumor ; Gastrointestinal autonomic nerve tumor ; Electron microscopy ; Immunohistochemistry ; Gastrointestinal tract
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Sixteen gastrointestinal stromal tumors (GISTs) were studied by immunohistochemical analysis and an ultrastructural procedure. The tumor locations were as follows: esophagus (2), stomach (7), small intestine (3), and large intestine (4). Four of the lesions were classified as malignant, 2 as borderline, and 10 as benign. On the basis of the immunohistochemical analysis, the tumors were classified as follows: 1 as myogenic type, 2 as Schwann cell type, 8 as Cajal cell type (including 2 gastrointestinal autonomic nerve tumors, GANTs), and 5 as mixed-cell type. In each subtype the phenotype was compared to the ultrastructural findings. Myogenic and Schwann cell type revealed ultrastructurally smooth muscle differentiation and schwannian tumor. All 8 tumors of the Cajal cell type revealed interdigitating cytoplasmic processes with occasional clusters of filopodia. Two tumors were subdivided as GANT. Five tumors of mixed-cell type were composed of a mixture of cells with variable myogenic features or variable neural differentiation. We confirmed in this study that immunohistochemical analysis reflected electron microscopic findings.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050005
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  • 3
    Digitale Medien
    Digitale Medien
    Reduction of cytochemical ecto-ATPase activities in keratin 8-deficient FVB/N mouse livers (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 209-212 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words Keratin ; Bile canaliculi ; Ecto-ATPase ; Transgenic mice ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Keratin 8 (K8) and keratin 18 are the intermediate filament proteins that are expressed in hepatocytes. A K8-deficient FVB/N mouse is a unique animal model for assessing the contribution of keratin intermediate filaments (IFs) to the structural and functional integrity of hepatocytes. Hepatocytes from homozygous (−/−) K8-deficient mice manifest a reduced bile acid secretion and an increased fragility to mechanical stress and hepatotoxic drugs. Hepatocytes from heterozygous (+/−) mice are more susceptible to drug-induced injury. Immunofluorescent microscopy revealed that hepatocytes from (+/−) mice maintained K8 IFs and F-actin that are similar to those in wild-type (+/+) mouse hepatocytes. In (−/−) mouse hepatocytes, K8 protein was negative and F-actin presented a coarse and irregular pattern. Ecto-ATPase, detected by enzyme histochemistry and observed by electron microscopy, was reduced in the bile canaliculi of both (+/−) and (−/−) mouse livers, in comparison with that of (+/+) mouse livers. These results reveal for the first time different microscopical findings regarding the livers of these three genotypes. They also suggest that the reduction of ecto-ATPase plays a role in the increased fragility of (+/−) and (−/−) mouse livers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050004
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  • 4
    Digitale Medien
    Digitale Medien
    Ultrastructural and immunohistochemical study of small cell neuroendocrine carcinoma of the parotid gland (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 122-126 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words Small cell neuroendocrine carcinoma ; Parotid gland ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A case of small cell neuroendocrine carcinoma of the parotid gland is presented with immunohistochemical and electron microscopic studies. Small cell neuroendocrine carcinoma is extremely rare and is often difficult to distinguish from malignant lymphoma, adenoid cystic carcinoma, and undifferentiated carcinoma. Under light microscopy, the tumor cells consisted of solid sheets and nests of small tumor cells. Immunohistochemically, they were positive for KL-1 and EMA, and focally positive for NSE and synaptophysin. Observation using an electron microscope showed membrane-bound neuroendocrine granules in some tumor cells. Histological evaluation indicated that the present case was small cell carcinoma of the parotid gland, showing a neuroendocrine variety.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050018
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  • 5
    Digitale Medien
    Digitale Medien
    Electron microscopic stereology of capillary endothelial cells and cardiomyocytes in artificially arrested canine hearts (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 151-160 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words Heart ; Ultrastructure ; Capillaries ; Endothelium ; Stereology ; Cardioplegic solutions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In open heart surgery and transplantation, sufficient structural preservation of the myocardium immediately following cardioplegic arrest is a precondition for overcoming ischemia and for resumption of postischemic function. Therefore, we compared the protective effect of three clinically applied cardioplegic solutions with fibrillating and beating hearts using structural criteria. Left ventricular samples were taken from (1) beating, or (2) fibrillating or arrested hearts following coronary perfu-sion with (3) St. Thomas' Hospital solution, (4) histidine tryptophane ketoglutalate (HTK) (Custodiol), or (5) University of Wisconsin (UW) solution and fixed by immersion. Ultrastructural differences in the swelling of capillary endothelial cells and myocytes were quantitatively evaluated using stereological methods. Endothelial cells were somewhat more swollen after St. Thomas perfusion than those in beating and fibrillating hearts. HTK-arrested hearts showed significantly lower values for cellular edema than beating hearts. UW perfusion resulted in the (significantly) lowest degree of endothelial cell edema. Edematous changes in myocytes were significantly greater in St. Thomas-arrested hearts than in UW- or HTK-arrested hearts. Cardiomyocyte edema in beating and fibrillating hearts was comparable to that in St. Thomas-perfused hearts. Thus, the stereol-ogical analysis revealed significant differences between cardioplegic solutions in structural preservation of myocardial ultrastructure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050022
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  • 6
    Digitale Medien
    Digitale Medien
    Secretory carcinoma of the breast: an immunohistochemical and ultrastructural study (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 50-56 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words: Secretory carcinoma ; Breast ; Intracytoplasmic lumina ; Immnohistochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report a rare case of secretory carcinoma of the breast in a 50-year-old Japanese woman. The patient had been aware of a right breast tumor for 8 years, but had left it untreated. The tumor enlarged in size and became painful, and she visited our hospital. Breast carcinoma was diagnosed, and mastectomy was performed. Histopathological examination revealed features of a secretory carcinoma characterized by prominent secretory activity in the glandular and microcystic spaces, with some areas showing a follicular pattern resembling the thyroid gland. The secretory material was PAS-positive and immunohistochemically α-lactalbumin-positive. Ultrastructurally, the tumor cell contained many secretory vacuoles in the cytoplasm. In addition, extracellular and intracytoplasmic lumina were conspicuous; these were lined by microvilli projection and contained secretory material. By flow cytometric analysis, the DNA index was 1.14, which was diploid, showing relatively low proliferative activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050008
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  • 7
    Digitale Medien
    Digitale Medien
    Ultrastructure of Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus-8 (HHV-8) in a primary effusion lymphoma cell line treated with tetradecanoyl phorbol acetate (TPA) (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 94-99 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words KSHV ; HHV-8 ; TPA ; Ultrastructure ; Primary effusion lymphoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The ultrastructure of Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus-8 (HHV-8) has not yet been fully elucidated, although some findings have been reported using primary effusion lymphoma (PEL) cell lines, KS-1, harboring no Epstein–Barr virus (EBV) coinfection. In the present study, detailed fine structural examination of KSHV/HHV-8 was performed after stimulation of the PEL-derived cell line KS-1 with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in vitro. While unstimulated KS-1 cells contained a small number of intranuclear virus particles associated with no extracellular mature particles, KS-1 cells stimulated with TPA produced many extracellular mature particles as well as intranuclear particles, in addition to interesting tubulo-reticular structures and aggregated tubular structures in vesicles. The induced intranuclear particles were empty, doughnut shaped, and dense cored, with outer and inner diameters of 100–110 nm and 60–70 nm, respectively. Dense-cored extracellular mature particles were 150–160 nm in diameter, and some contained doughnut-shaped cores, together with a few megaloviruses, 260 nm in outer diameter. These findings indicate that KS-1 cells treated with TPA can produce extracellular mature particles as well as intranuclear particles, which were proven to be KSHV/HHV-8.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050014
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  • 8
    Digitale Medien
    Digitale Medien
    Docetaxel-induced apoptosis in the mitotic phase: electron microscopic and cytochemical studies of human leukemia cells (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 167-174 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words Apoptosis ; Docetaxel ; Human leukemia cell ; DNA fragmentation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We induced apoptosis in cells of the human leukemia cell line HL-60 using an antitumor agent, docetaxel (Taxotere), and investigated apoptosis in various aspects using in situ end-labeling (ISEL) of DNA, DNA fragmentation assay, flow cytometry, and electron microscopy. Because it inhibits depolymerization of tubulin, docetaxel is thought to arrest the cell cycle at the mitotic stage and to exert an antitumor effect. In this study, accumulation of docetaxel-treated cells at the G2/M phase was detected using flow cytometry. On ISEL of DNA, DNA fragmentation was observed at the mitotic stage. On electron microscopy, the nuclei of apoptotic cells lost their nuclear membranes, as do cells at mitosis, demonstrating that the cells were arrested mainly at the M phase in the cell cycle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050024
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  • 9
    Digitale Medien
    Digitale Medien
    The protective effect of hepatocyte growth-promoting factor (pHGF) against carbon tetrachloride-induced acute liver injury in rats: an ultrastructural study (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 184-192 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words pHGF ; HGF ; Acute liver injury ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The protective effect of hepatocyte growth-promoting factor (pHGF) against CCl4-induced acute hepatitis in rats was examined by light and electron microscopy. Hepatocyte growth-promoting factor, purified from infant pig liver in an active form, has been used clinically in patients with hepatitis in China. Four hours after administration of CCl4, a single dose of pHGF was administered intraperitoneally. Six hours after administration of CCl4, inhibition of CCl4-induced hepatic necrosis and hepatocytes with severely dilated endoplasmic reticula were evident in rats treated with pHGF. At 48 h post administration, most hepatocytes had recovered, and not only mitotic hepatocytes (10–13 mitotic cells/100) but also mitotic Kupffer cells were observed. At 72 h, it was evident that the differentiation of hepatic stellate cells (Ito cell) into myofibroblast-like cells and the development of fibrosis around the central veins was prevented by pHGF. These results suggested that (1) pHGF may stabilize cell membranes, (2) pHGF acts as a mitogen not only for hepatocytes but also for Kupffer cells, and (3) pHGF prevents fibrogenesis in the case of CCl4-induced liver injury by preventing the differentiation of hepatic stellate cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050026
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  • 10
    Digitale Medien
    Digitale Medien
    Changes in cerebral blood flow and blood brain barrier in the gerbil hippocampal CA1 region following repeated brief cerebral ischemia (1999)
    Springer
    Medical electron microscopy 32 (1999), S. 175-183 
    Details
    ISSN: 1437-773X
    Schlagwort(e): Key words Cerebral blood flow ; Blood–brain barrier ; Repeated brief cerebral ischemia ; Hippocampal CA1 ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Neuronal damage and changes in cerebral blood flow (CBF) and the permeability of the blood–brain barrier (BBB) following repeated brief periods of ischemia were studied in Mongolian gerbils. The cerebral ischemia was produced by three repeated occlusions of bilateral common carotid arteries for 3 min at 1-h intervals. CBF and permeability of the BBB were examined with tracers (China ink and silver nitrate) at 1, 3, and 7 days post ischemia using light and electron microscopy. Three days after the reperfusion, significant extravasation of tracers, consequential reduction of CBF, extensive neuronal destruction, and intravascular platelet aggregation were observed. Such vascular changes in the CA1 region were more severe than those in the frontal cortex. These findings strongly support the view that microcirculatory disturbance may be a mechanism responsible for delayed neuronal death in the CA1 region of the hippocampus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007950050025
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  • 11
    Digitale Medien
    Digitale Medien
    Melanin pigmented oncocytic metaplasia of the nasopharynx (1999)
    Springer
    Virchows Archiv 434 (1999), S. 455-457 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Melanin ; Oncocytic metaplasia ; Nasopharynx ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  A 64-year-old man presented with a history of discomfort of the throat of a few weeks’ duration. Nasoscopic examination revealed multiple small, brown pigmentations at the left suprapharynx, the base of the left nasal cavity and the pharyngeal openings of the auditory tube on both sides. Microscopically, the lesion showed a glandular pattern of oncocytic epithelium with abundant pigmented granules and melanophages in the surrounding stroma. Immunohistochemically, the dendritic cells in the basal layer were positive for S-100 protein. Electron microscopic study revealed numerous fully melanized melanosomes and hypertrophied mitochondria in the oncocytic cells. Oncocytic cells do not produce melanin for themselves, melanin granules apparently being transferred from the adjacent dendritic cells to the oncocytic cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004280050366
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  • 12
    Digitale Medien
    Digitale Medien
    Ultrastructural study of the destructive and repair processes in pulmonary inflammation and following endobronchial laser therapy (1999)
    Springer
    Virchows Archiv 435 (1999), S. 13-19 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Inflammation of the lung ; Biopsy ; Ultrastructure ; Laser therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Examination of 127 biopsy specimens from 45 patients with inflammatory lung diseases showed changes consistent with increased permeability of the capillary endothelial cells as an initial stage in the development of the inflammatory reaction. Associated interstitial oedema, deformation of the interalveolar septa, and structural disorganization of alveolar epithelium cells occur, and local microcirculatory problems result in tissue hypoxia and fibrosis. The ultimate morphological picture is determined largely by the intensity of repair. Laser biostimulation minimizes the inflammation and stabilizes fibroplastic process.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004280050389
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  • 13
    Digitale Medien
    Digitale Medien
    Evaluation of muscle capillary basement membrane in inflammatory myopathy (1999)
    Springer
    Virchows Archiv 435 (1999), S. 58-61 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Capillary basement membrane ; Inflammatory myopathy ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The capillary basement membranes from 16 skeletal muscle biopsies from patients with a clinical and histological diagnosis of inflammatory myopathy and from six controls were analysed ultrastructurally and morphometrically. Resin sections from 244 endomysial capillaries were examined by light microscope, and the results were correlated with findings seen in electron micrographs of these capillaries. The ultrastructural morphometric measurements and the statistical analysis showed that the capillary basement membrane was thick and multilaminated in 87% specimens affected by inflammatory myopathy. No thick or multilaminated basement membrane was observed in controls. In inflammatory myopathy the endomysial space next to the capillaries contained an increased amount of collagen fibrils and showed signs of a chronic reparative process. It is suggested that the thick multilaminated basement membrane in inflammatory myopathy represents an advanced stage of vascular regeneration.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004280050395
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  • 14
    Digitale Medien
    Digitale Medien
    The effects of cold-restraint stress on urinary bladder wall compared with interstitial cystitis morphology (1999)
    Springer
    Urological research 27 (1999), S. 454-461 
    Details
    ISSN: 1434-0879
    Schlagwort(e): Key words Cold-restraint stress ; Urinary bladder ; Interstitial cystitis ; Mast cell ; Urothelium ; Ultrastructure ; Ruthenium red ; Flow cytometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Stress is associated with many diseases of unknown aetiology. This study demonstrates the effects of cold-restraint stress on the morphology of the urinary bladder. Additionally, it compares the results obtained with the morphology of the interstitial cystitis. The animals were subjected to three hours of cold-restraint stress and then starved for 48 h. The morphology and histochemistry of the urinary bladder was investigated with light and electron microscopy. The proliferative activity was analysed via flow cytometry. Increased and degranulated mast cells in the mucosa, leucocyte infiltration in the lamina propria, vacuole formation in the urothelial cells, loose tight junction, dilated intercellular spaces and altered proliferative activity were observed in the stress group when compared with the control. The increase in the number of mast cells and especially degranulated mast cells and vacuole formation and the loose tight junction of the urothelium correlated with the histopathological findings of interstitial cystitis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002400050135
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  • 15
    Digitale Medien
    Digitale Medien
    Bunina bodies in amyotrophic lateral sclerosis on Guam: a histochemical, immunohistochemical and ultrastructural investigation (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 150-156 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Amyotrophic lateral sclerosis ; Bunina body ; Guam ; Immunohistochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract An investigation of Bunina bodies is important when studying the pathoetiology and pathomechanisms involved in amyotrophic lateral sclerosis (ALS). It may serve as a clue essential for the study of the pathogenesis of Guamanian amyotrophic lateral sclerosis (ALS-G), and it may provide a means of answering the question of whether ALS-G is the same disease as classical ALS or a different entity. In ALS-G, however, no precise histochemical, immunohistochemical, or detailed ultrastructural examination has been published to date. To elucidate the pathological differences/similarities of Bunina bodies between classical ALS and ALS-G, we performed histochemical, immunohistochemical, topographic and ultrastructural examinations. Histochemically, hematoxylin and eosin, Masson’s trichrome, methylgreen-pyronin, phosphotungstic acid-hematoxylin, Klüver-Barrera, Bodian and periodic acid-Schiff staining were utilized. Immunohistochemical examination was performed using antibodies for cystatin C, ubiquitin, Tau-2, Cu/Zn superoxide dismutase, phosphorylated neurofilament and glial fibrillary acidic protein. Histochemical findings were consistent with those previously described for classical ALS. The immunohistochemical study showed that in ALS-G Bunina bodies were intensely labeled by an anti-cystatin C antibody. Topographic examination demonstrated that Bunina bodies were distributed in the spinal anterior horns and Clarke’s column in the spinal cord. Ultrastructurally, Bunina bodies were composed of electron-dense amorphous/ granular material accompanied by vesicular structures and neurofilaments. The results of the present study have revealed that the pathological features of Bunina bodies in ALS-G are identical to those seen in classical ALS. These findings strongly suggest that a similar degenerative process occurs in the spinal anterior horn cells in both ALS-G and classical ALS.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010051063
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  • 16
    Digitale Medien
    Digitale Medien
    Familial inclusion body myopathy with desmin storage (1999)
    Springer
    Acta neuropathologica 97 (1999), S. 509-514 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Hereditary inclusion body myopathy ; Desmin storage myopathy ; Ultrastructure ; Immmunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report two adult familial cases of inclusion body myopathy (IBM) with desmin storage in skeletal muscle. Clinically, both patients presented late-onset, progressive, symmetrical, both proximal and distal muscle weakness. Muscle biopsy findings were identical in both cases and consisted of marked variability in fiber size, increased number of central nuclei and vacuolation involving 10% of fibers. Single or multiple vacuoles were located subsarcolemmally or in the center, and were rimmed by basophilic material. At the ultrastructural level, tubulofilamentous nuclear and cytoplasmic inclusions of 16–21 nm in diameter were frequently observed. In addition, large subsarcolemmal and central deposits composed of electron-dense granular material were present in many fibers. Immunocytochemistry revealed staining for desmin, vimentin and ubiquitin within both inclusions and vacuolated fibers. Possible structural and functional associations between these two types of muscle changes remain unclear. They may either represent two coexistent disease processes or merely reflect an abnormal form of muscle fiber degradation, with unidentifiable specificity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010051021
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  • 17
    Digitale Medien
    Digitale Medien
    The anchoring zone in the human placental amnion: bunches of oxytalan and collagen connect mesoderm and epithelium (1999)
    Springer
    Anatomy and embryology 200 (1999), S. 81-90 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Key words Elastic fibre system ; Microfibrils ; Collagen type IV ; Ultrastructure ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  This study deals with the examination of the elastic fibre system as well as collagen fibrils and collagen type IV in the amnion of the human chorionic plate of uncomplicated pregnancies at term. In organs other than placenta, the elastic fibre system comprises elastic fibres, elaunin and oxytalan microfibrils. The investigation was performed by light and electron microscopy and immunocytochemistry. Abundant oxytalan fibres were present in all amnionic layers, while no elastic fibres were found. Oxytalan microfibrils formed a broad subepithelial layer and were intermingled with collagen fibrils in the subjacent compact layer and in the amnionic mesoderm. Light microscopically, bunches containing orcein-stained oxytalan and collagen-type-IV-immunostained microfibrils were seen rising from the amnionic mesoderm perpendicularly towards the epithelial layer, where they obviously inserted. It can be assumed that the subepithelial microfibrillar layer and the following compact layer form an anchoring zone between the amnionic mesoderm and the epithelium that may contribute to the maintenance of strength. The ultrastructure of the bunches clearly showed collagen fibrils mixed with oxytalan microfibrils. No collagen type I-immunostaining was found in the bunches. After pretreatment of cryostat sections with elastase, oxytalan-orcein-staining was absent, but collagen type IV-immunoreactivity was not altered. Furthermore, after oxytalan-orcein-staining resp. anti-collagen type IV incubation, all positive fibres revealed an identical morphological pattern. We propose that oxytalan and collagen type IV may represent further members of the microfibril complex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004290050262
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  • 18
    Digitale Medien
    Digitale Medien
    Subretinal macrophages in the developing eye of eutherian mammals and marsupials (1999)
    Springer
    Anatomy and embryology 200 (1999), S. 551-558 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Key words Retina ; Development ; Retinal pigment epithelium ; Microglia ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Blood-borne mononuclear cells invade the developing retina via the hyaloid vasculature at the optic nerve head. Following removal of apoptotic cell debris they give rise to the network of resident microglia. The population of cells recently described in the peripheral subretinal space of developing human eyes may represent a further population of macrophages destined to become microglia. The aim of the present study was to confirm the presence of subretinal macrophages in the developing eye in other mammalian species and perform preliminary immunophenotypic analysis in rat tissues. The range of species chosen included eutherian mammals (rat and rabbit) and marsupials (wallaby and opossum). Ocular tissues from a range of developmental stages were studied by scanning electron microscopy and transmission electron microscopy. Distinctive networks of dendriform and pleomorphic macrophages were observed by scanning electron microscopy in the peripheral subretinal space of D2 rabbits, newborn and D2 rats and D75 wallaby. Transmission electron microscopic studies of D2 rabbit, newborn and D2 rat and all ages of North American opossum revealed cells with the ultrastructural features of macrophages in the peripheral subretinal space, cilio-retinal junction and between ciliary epithelial cells. Preliminary immunoperoxidase studies using a panel of anti-leukocyte monoclonal antibodies on frozen sections of rat ocular tissues (newborn, D2 and D4) revealed ED1+ Ox42+ ED2+ but Ox6– cells in the peripheral subretinal space, peripheral retina and ciliary body epithelia. The data confirms that subretinal macrophages are a feature of the developing eye in a broad range of mammalian species and immunophenotypic evidence leads the author to postulate that these cells arise from the ciliary body vasculature and may migrate into peripheral neural retina and mature into resident microglia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004290050303
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  • 19
    Digitale Medien
    Digitale Medien
    Motor neuron disease with predominantly upper extremity involvement: a clinicopathological study (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 645-650 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Amyotrophic lateral sclerosis ; Autopsy ; Electron microscopy ; Immunocytochemistry ; Motor ; neuron disease
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We report two autopsy cases of motor neuron disease (MND) patients with an unusual type of muscular atrophy predominantly affecting the shoulder girdle and the upper extremities with proximal dominance. Both patients are considered to be clinically categorized into the El Escorial suspected form of amyotrophic lateral sclerosis (ALS). At autopsy, they showed marked loss of spinal anterior horn cells accompanied by astrogliosis positively immunostained with anti-glial fibrillary acidic protein antibody at the cervical level. At the lumbosacral level, anterior horn neurons were relatively well preserved and Bunina bodies, ubiquitin-positive skein-like inclusions and Lewy body-like inclusions were observed in the remaining neurons. In one patient, brain stem motor neurons (nerves V, VII, XII) and motor cortex, including Betz cells, were also affected and the corticospinal tracts were degenerated at the level of the thoracic and lumbar spinal cord. Pathological findings of this patient are consistent with those of ALS. In the other patient, the motor cortex, brain stem motor nuclei and the corticospinal tracts were well preserved, which is pathologically compatible with progressive spinal muscular atrophy. These patients with such a peculiar pattern of progressive muscular atrophy should be placed in a subgroup of ALS.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010051131
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  • 20
    Digitale Medien
    Digitale Medien
    A developmental study using three antibodies (VOBM1, VOBM2, and VOM2): immunocytochemical and electron microscopical analysis of the luminal surface of the rat vomeronasal sensory epithelium (1999)
    Springer
    Anatomy and embryology 199 (1999), S. 215-224 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Key words Vomeronasal organ ; Microvilli ; Monoclonal antibody ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The development of the rat vomeronasal organ was studied morphologically and immunocytochemically, using the monoclonal antibodies (MAbs) VOBM1, VOBM2 and VOM2 that react with the luminal surface of the vomeronasal sensory epithelium. Postnatal day (P) 7, 14, 21, 28, 35 and adult animals were examined. The vomeronasal organ and the blood vessel of the organ markedly increased in size and the vomeronasal glands increased in number between P7 and P14. At P35, the shape of the vomeronasal organ was similar to that of the adult but its size was slightly smaller. Electron microscopy showed that only a few scattered microvilli were present on supporting cells, and receptor cells were immature at P7. At P21, well-branched microvilli of the receptor cells and many microvilli of the supporting cells were observed on the luminal surface of the sensory epithelium. At P35, most apical endings of supporting cells and receptor cells were covered with numerous microvilli. Less developed areas were also present at the luminal surface of the epithelium at P35. At P7, immunoreactivities of the three antibodies were observed as discontinuous thin-layered bands only on the luminal surface of the sensory epithelium and no immunoreactivity was observed in other regions of the vomeronasal organ. Immunoreactivities of the VOBM1, VOBM2 and VOM2 increased with age and were observed as continuous thin-layered bands on the luminal surface of the epithelium by P35. These finding suggest that the development of the vomeronasal organ continues after birth and that the organ may reach maturity just before puberty (P42–49).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004290050222
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  • 21
    Digitale Medien
    Digitale Medien
    A new combined Bodian-Luxol technique for staining unmyelinated axons in semithin, resin-embedded peripheral nerves: a comparison with electron microscopy (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 323-329 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Unmyelinated fibers ; Peripheral nerve ; Electron microscopy ; Histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Quantitation of unmyelinated fibers (UF) in peripheral nerves has classically relied upon ultrastructural morphometry. Because this method is time-consuming, it is not typically performed in routine analysis of nerve biopsies. We applied the Bodian-Luxol technique to detect unmyelinated axons by light microscopy on semithin sections from resin-embedded nerve tissue. Estimates were compared to ultrastructural counts. The staining appeared highly specific for axons. Excellent correlation was found between optic densities and the population of UF larger than 0.5 μm. The smallest profiles detected by light microscopy had a diameter close to 0.6 μm. This new technique is not a substitute for ultrastructural quantitative morphometry of UF, as very small unmyelinated axons, especially regenerating ones, can not be reliably visualized. However, it provides a valuable light microscopic method for evaluating axonal loss among UF.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010051088
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  • 22
    Digitale Medien
    Digitale Medien
    Ultrastructural localization of phosphorylated eIF2α [eIF2α(P)] in rat dorsal hippocampus during reperfusion (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 493-505 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Ischemia ; Protein synthesis ; Translation ; Ultrastructure ; Hippocampus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract During post-ischemic brain reperfusion there is a substantial reduction of protein synthesis in selectively vulnerable neurons. Normal protein synthesis requires a functional translation initiation complex, a key element of which is eukaryotic initiation factor 2 (eIF2), which in a complex with GTP introduces the met-tRNAi. Phosphorylation of Ser51 on the α subunit of eIF2 [eIF2α(P)] generates a competitive inhibitor of eIF2B, thereby preventing the replenishment of GTP onto eIF2, thus blocking translation initiation. It has been shown that the conditional expression of an eIF2α mutant (Asp substituted for Ser51) imitating the negative charge of Ser51 (P) induces apoptosis. During the first 10 min of post-ischemic reperfusion, there is an approximately 20-fold increase in eIF2α(P) seen in the cytoplasm of CA1 hippocampal neurons, and, by 1 h, there is also accumulation of eIF2α(P) in the nucleus. We utilized post-embedding electron microscopical immunogold methods to examine the localization of eIF2α(P) during reperfusion. Immunogold particles (10 nm) were concentrated chiefly along the rough endoplasmic reticulum and in association with the membranes of the nuclear envelope in CA1 neurons. Aggregations of gold particles in the nucleus were concentrated: (1) within and around the nucleolus, (2) associated to strands of heterochromatin, and (3) along putative nuclear filaments. The presence of eIF2α(P) in the nucleolus probably reflects its association with nascent ribosomal subunits. The β-subunit of eIF2 has a zinc finger and polylysine blocks analogous to those on other proteins that affect transcription. The association of eIF2α(P) with chromatin may have important implications for transcription.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010051115
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  • 23
    Digitale Medien
    Digitale Medien
    Structural identification and characterization of arteries and veins in the placental stem villi (1999)
    Springer
    Anatomy and embryology 199 (1999), S. 407-418 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Key words Placenta ; Vascular wall ; Smooth muscle cell ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The vascular wall structure in the human full-term placental villi of normal pregnancy was studied by means of light and electron microscopy with an improved technique of perfusion fixation and tissue preparation. We observed 81 sections of stem villi that showed cross-sectional profiles of paired vessels in their center. Both vascular walls contained a large amount of extracellular matrix and no elastic lamina between smooth muscle cells of the media, making identification of the artery and the vein quite difficult at first sight. We then noted that the density of the smooth muscle cell population was always considerably higher in one than the other, and identified the former as artery and the latter as vein on the basis of their connection with larger arteries and veins running on the chorionic plate. Between the paired vessels, the artery had a smaller caliber than the vein, and the ratio of venous to arterial caliber was distributed from 1.0 to 2.5. The thickness of media was usually thicker in the vein than in the artery. Clusters of elastic fibers were found occasionally in the media of arteries and veins, and basement membrane-like materials were associated frequently with the elastic fibers and were distributed widely in the media as well as in the adventitia. In the veins, the smooth muscle cells of the most superficial part of the media contained well-developed rough endoplasmic reticulum and Golgi apparatus, indicating differentiation to secrete extracellular matrices. The present study revealed the difference of wall structure between arteries and veins in the placental stem villi for the first time at the ultrastructural level, and suggested differentiation of venous smooth muscle cells, possibly by some influence from the luminal side.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004290050239
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  • 24
    Digitale Medien
    Digitale Medien
    Immunohistochemical, conventional and immunoelectron microscopical characteristics of periodic acid-Schiff-positive granules in the mouse brain (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 31-38 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Polyglucosan body ; Periodic ; acid-Schiff-positive granules ; Mouse brain ; Immunohistochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Periodic acid-Schiff-positive granules (PGs) appear in the mouse brains in relation to advancing age. The exact location and pathophysiological significance of PGs, however, are not fully understood. The incidence, staining properties, and topographical distributions of PGs in the brains of 17 AKR mice ranging in age from 7 to 18 months were examined histochemically and immunohistochemically using antibody KM279 raised against a polyglucosan. In addition, to define the precise site of PG formation, we investigated the brains of 4 AKR mice of 24 months of age using conventional and immunoelectron microscopy. PGs were seen in all mice examined and the levels were increased with age. The PGs were located predominantly in the hippocampus and, to a lesser extent, in the cerebellum and olfactory bulb. Immunohistochemically, PGs in the hippocampus and cerebellum were labeled uniformly with KM279. On immunoelectron microscopy with this monoclonal antibody, the fibrillar or membranous structures corresponding to PGs seen using light microscopy were labeled specifically with gold particles. With conventional electron microscopy, fibrillar or membranous structures were seen along with synaptic vesicles and dense-core granules. Moreover, around the cells containing PGs, a few synaptic junctions with neighboring cells were observed, indicating that the cells contributing to formation of PGs were neuronal cells. The positive immunoreactivity of AKR mouse PGs for the antibody KM279 suggests that the PGs and similar structures in other species may share a common antigenicity. Thus, it is assumed that PGs in AKR mice might result from some abnormalities in glucose metabolism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010051048
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  • 25
    Digitale Medien
    Digitale Medien
    Breached cerebral glia limitans-basal lamina complex in Fukuyama-type congenital muscular dystrophy (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 330-336 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Micropolygyria ; Electron microscopy ; Frontal lobe ; Perivascular space ; Dot-like structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We have reported breaches of glia limitans (GL)-basal lamina (BL) complex with protruding neuroglial tissue in Fukuyama-type congenital muscular dystrophy (FCMD) fetus brain and suggested that some basic deficits in the GL-BL complex may have a pivotal role in formation of micropolygyria in FCMD. We therefore investigated the cerebral GL-BL complex in seven FCMD cases (12–27 years of age), in three cases of Duchenne muscular dystrophy (17–25 years of age) and in two non-neurological controls (28 and 33 years of age). The frontal lobe cortex was examined immunocytochemically using antibodies against collagen type IV and laminin in each case, and ultrastructurally in an adult case of FCMD. In FCMD, the BL of the cortical surface was frequently breached with protruding neural tissue that ultrastructurally showed frequent synapses, neurites that had parallel arranged microtubules, and astrocytic processes. The outermost surface of this tissue was only partly lined by a BL. In the region of the gyral adhesion of micropolygyria, the perivascular space of the apparently entrapped meningeal blood vessels was occupied by neuroglial tissue, which is assumed to have invaded through the occasionally seen breaches of the perivascular GL-BL complex. Electron microscopy of the intruding tissue showed frequent synapses, microtubule-containing neurites and astrocytic processes. No breached GL-BL complex was found in any of the non-FCMD cases. These findings indicate that in FCMD, the cerebral GL-BL complex continues to have a crucial deficit with resulting breaches through which neuroglial tissue protrudes, promoting adhesion of the adjacent cerebral gyri during brain development before and after birth.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010051089
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  • 26
    Digitale Medien
    Digitale Medien
    The visualization of a new class of traumatically injured axons through the use of a modified method of microwave antigen retrieval (1999)
    Springer
    Acta neuropathologica 97 (1999), S. 335-345 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Key words Amyloid precursor protein ; immunoreactivity ; Axonal injury ; Microwave antigen retrieval ; Traumatic brain injury ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Antibodies to the amyloid precursor proteins (APP) have become routine markers for detecting traumatically induced axonal injury (AI) in animals and man. Unfortunately, the techniques used to visualize these proteins are not compatible with routine electron microscopic (EM) analysis. In the current communication, we describe a method for the ultrastructural visualization of antibodies to APP and, using this method, we identify a previously unrecognized population of traumatically injured axons. Rats were subjected to an impact acceleration traumatic brain injury and allowed to survive 30 min to 3 h postinjury. The animals were then perfused, their brains sectioned on a vibratome and the sections prepared for immunocytochemistry using a computer-controlled microwave capable of temperature regulation. The use of temperature-controlled microwave energy unmasked APP antigenic epitopes without sacrificing ultrastructural detail. The APP antibody was found in two distinct populations of reactive axons that differed in size, morphology, location, and temporal progression. Comparable to previous descriptions, one population showed traumatically related reactive changes that led to swelling and disconnection. The other population, however, revealed unanticipated changes reflected in nodal and paranodal swelling of small continuous fibers that showed no evidence of disconnection during the time periods assessed. These studies provide new insight into the complexity of the pathobiology of AI, while describing a novel approach for enhancing APP immunoreactivity at the EM level.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004010050996
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  • 27
    Digitale Medien
    Digitale Medien
    Synaptology and ultrastructural characteristics of laryngeal cricothyroid and posterior cricoarytenoid motoneurons in the nucleus ambiguus of the rat (1999)
    Springer
    Anatomy and embryology 200 (1999), S. 301-311 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Key words Intrinsic laryngeal motoneurons ; Cholera toxin HRP ; Ultrastructure ; Swallowing ; Respiration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The laryngeal motoneurons innervating the cricothyroid muscle (CT) are located in the semicompact formation just ventral to the rostral part of the compact formation of the nucleus ambiguus. The motoneurons innervating the posterior cricoarytenoid muscle (PCA) are located in the loose formation. We retrogradely labeled the CT and the PCA motoneurons using cholera toxin subunit B-conjugated horseradish peroxidase, and determined the ultrastructure and synaptic organization of these neurons. The CT and the PCA motoneurons had the appearance of α-motoneurons, i.e., large, oval or polygonal cells containing well-developed organelles and a prominent spherical nucleus. Two kinds of neurons were recognized among the PCA motoneurons. The one (PCA-A) was significantly smaller than the other (PCA-B). The average number of axosomatic terminals in a section was significantly largest in the PCA-B (56.6), smaller in the PCA-A (36.0), and smallest in the CT (32.3) neurons. Most of the axosomatic terminals (64.7%) contained pleomorphic vesicles and made symmetric synaptic contacts (Gray’s type II) with the PCA-A neurons, while more than 60% contained round vesicles with asymmetric synaptic contacts (Gray’s type I) in the CT (69.5%) and the PCA-B (60.6%) neurons. A few terminals associated with subsurface cisterns were present on all laryngeal motoneurons. These results indicated that the CT motoneurons may receive mostly excitatory terminals, whereas the PCA muscle may be regulated by neurons having many inhibitory terminals, and neurons having many excitatory terminals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004290050281
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  • 28
    Digitale Medien
    Digitale Medien
    The cytoskeleton of the myenteric neurons during murine embryonic life (1999)
    Springer
    Anatomy and embryology 199 (1999), S. 459-469 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Key words Differentiation ; Electron microscopy ; Histochemistry ; Microtubules ; Neurofilaments
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The organization of the cytoskeleton has been studied during mouse differentiation in cells of the myenteric neuronal lineage. The entire gut was examined starting from day 12.5 of embryonic life (E12.5) until birth (P0). Immunocytochemistry was performed to evaluate the expression of five of the most represented neurofilaments proteins (the low, NF-L, medium, NF-M, and heavy, NF-H, molecular weight subunits, α-internexin and peripherin) and of two of the microtubule-associated proteins (MAP1 and MAP2a+2b). In parallel, the appearance in the differentiating myenteric neurons of filamentous and microtubular structures and their intracytoplasmatic distribution were observed under the electron microscope. A differential immunohistochemical expression of the structural proteins was found. Immature cells expressed α-internexin, peripherin, NF-M and MAP1 by day E12.5; α-internexin expression was strong in these cells, but gradually decreased with age and was practically absent in adulthood. Conversely, the expression of the other three proteins increased with cell differentiation and was still present in adulthood. NF-L and NF-H expression appeared later, by day E16.5, and was weak for the entire pre- and postnatal life. MAP2a+2b was never expressed. Under the electron microscope, at day E12.5 the cytoskeleton was already organized in filamentous and microtubular structures. At this age neurofilaments were few and mainly located in the cell processes, and microtubules were numerous and mainly assembled in the neuritic growth cones, together with synaptic vesicles. With ageing, neurofilaments and microtubules were ubiquitous in the neuron. Data obtained demonstrate that cytoskeletal proteins gradually accumulate in the cells of the neuronal lineage in parallel with the organization of the cytoskeletal structures, which in turn mediate important neural events by the earliest stages of murine embryonic life, including growth of nerve processes and initiation of axonal transport.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004290050244
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  • 29
    Digitale Medien
    Digitale Medien
    Light and electron microscopic immunohistochemical observations of p75 nerve growth factor receptor-immunoreactive dermal nerves in prurigo nodularis (1999)
    Springer
    Archives of dermatological research 291 (1999), S. 14-21 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Key words p75 nerve growth factor receptor ; (p75 NGFr) ; Immunoreactivity ; Ultrastructure ; Prurigo nodularis ; Nerve fiber
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Prurigo nodularis is an inflammatory skin disease characterized by neurohyperplasia. Neurotrophins and their receptors play a critical role in nerve growth, differentiation, maturation and maintenance, including cutaneous nerve fiber growth and innervation. They may also be responsible for events related to the growth and differentiation control of keratinocytes. To explore the exact distribution of the p75 low-affinity nerve growth factor receptor (p75 NGFr) in the cutaneous nerve components, p75 NGFr immunofluorescence as well as ultrastructural immunohistochemical studies were performed on prurigo nodularis lesional skin and normal human skin samples. The immunofluorescence results revealed that nerve fibers and bundles were increased in number and size in lesional upper dermis with stronger p75 NGFr immunoreactivity than in the corresponding normal tissue. At the ultrastructural level, a lot of nerve fibers clustered together in the prurigo nodularis dermal tissue. The axons were enlarged and branched, but the axons themselves seldom showed any NGFr immunoreactivity. The Schwann cell bodies were extended and irregularly shaped, and tended to separate into many branches enveloping the axons. The Schwann cell membrane showed strong p75 NGFr immunoreactivity. The perineurium cells also revealed strong p75 NGFr immunoreactivity. The Schwann cells inside the perineurium were less p75 NGFr-immunoreactive than those outside the perineurium. The membrane of certain basal keratinocytes showed NGFr immunoreactivity as well. The present results indicate that overexpression of p75 NGFr in Schwann cells and perineurium cells could contribute to the neurohyperplasia in prurigo nodularis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004030050378
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  • 30
    Digitale Medien
    Digitale Medien
    Larva-adult relationships in an ancestral dipteran: A re-examination of sensillar pathways across the antenna and leg anlagen of Chaoborus crystallinus (DeGeer, 1776; Chaoboridae) (1999)
    Springer
    Development genes and evolution 209 (1999), S. 103-112 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Key words Imaginal disc ; Axonal trajectories ; Ultrastructure ; Chaoborus (Insecta ; Diptera)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  In one of his classical studies on insect metamorphosis, Weismann compared the imaginal anlagen of the ancestral phantom midge, Chaoborus, with those of advanced brachycerans. We have expanded his findings on the relationships between larval and imaginal organs using electron microscopy and cobalt backfilling of the antenna and leg anlagen and the axonal trajectories of corresponding larval sensilla. We show that both primordia are confluent with the larval antennae and ”leg” sensilla (an ancestral Keilin organ), respectively. These fully developed larval organs represent the distal tips of the imaginal anlagen rather than separate cell clusters. The axons of the larval antenna and leg sensilla project across the corresponding anlagen to their target neuromeres within the central nervous system (CNS). Within the discs, nerves composed of these larval axons, developing afferent fibres and efferences ascending from the CNS are found. Both the structure of the primordia and the axonal trajectories thus relate the situation found in advanced brachycerans with that seen in more ancestral insects. In addition, the larval antennae, legs, wings and even the eyes possess very similar afferent pioneer trajectories supporting the idea that the described pattern is generally used in the ontogeny of sensory systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004270050232
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  • 31
    Digitale Medien
    Digitale Medien
    Megasporogenesis in Arabidopsis thaliana L.: an ultrastructural study (1999)
    Springer
    Sexual plant reproduction 12 (1999), S. 99-109 
    Details
    ISSN: 1432-2145
    Schlagwort(e): Key words Arabidopsis thaliana ; Megasporogenesis ; Meiosis ; Ultrastructure ; Cellular polarity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract  In this study, megasporogenesis of the plant model Arabidopsis thaliana was investigated by electron microscopy for the first time. The data described here could constitute a reference for future investigations of Arabidopsis mutants. During the beginning of meiosis the megaspore mother cell shows a polarity created by unequal distribution of organelles in the cytoplasm. Plastids accumulate in the chalazal region and long parallel saccules of endoplasmic reticulum, small vacuoles and some dictyosomes are found in the micropylar region. Plasmodesmata are abundant in the chalazal cell wall. The nucleus is almost centrally localized and contains a prominent excentric nucleolus and numerous typical synaptonemal complexes. After the second division of meiosis the four megaspores are separated by thin cell walls crossed by numerous plasmodesmata and do not show significant cellular organization. The young functional megaspore is characterized by a large nucleus and a large granular nucleolus. The cytoplasm is very electron dense due to the abundance of free ribosomes and contains the following randomly distributed organelles: mitochondria, a few short saccules of endoplasmic reticulum, dictyosomes and undifferentiated plastids. However, there is no apparent polarity, except for the distribution of some small vacuoles which are more abundant in the micropylar region of the cell. The degenerating megaspores are extremely electron dense and do not show any substructure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004970050178
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  • 32
    Digitale Medien
    Digitale Medien
    Studies of lectin receptors of rat microglia in culture: receptor distribution and internalization (1999)
    Springer
    Experimental brain research 124 (1999), S. 89-99 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Key words Microglial culture ; Brain macrophages ; Isolectin ; Ultrastructure ; Intracellular pathway
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  The present study examined the lectin labeling of diverse morphological forms of microglia in culture. Similar to amoeboid microglial cells in vivo, polymorphic microglia showed lectin labeling at their plasma membranes, as well as in a few cytoplasmic vesicles and vacuoles. This labeling pattern was observed in cultured microglia incubated with isolectin at 4°C for 30 min. Five minutes after the temperature was raised to 37°C, the surface lectin receptors appeared to be internalized, as shown by the occurrence of many subsurface lectin-labeled vesicles, vacuoles and tubule-like structures. With longer incubation (up to 1–2 h at 37°C), many lysosomes and a few trans-Golgi saccules and associated lysosome-like structures became labeled. Concomitant with these changes was a reduction of lectin labeling at the plasma, with labeling having vanished in most of the cells after 1–2 h of incubation. By 24 h, only a few cells retained surface lectin labeling. It appears, therefore, that irrespective of morphology, lectin labeling (including its intracellular pathway) of microglia in culture parallels that of amoeboid microglia in vivo. This would offer a useful model for the study of lectin turnover in microglia and help to explain the roles of such receptors in microglial differentiation and function.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002210050603
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  • 33
    Digitale Medien
    Digitale Medien
    Recovery of synapses in axotomized adult cat spinal motoneurons after reinnervation into muscle (1999)
    Springer
    Experimental brain research 125 (1999), S. 19-27 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Key words Nerve injury ; Nerve repair ; Retrograde reaction ; Regeneration ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Peripheral axotomy of adult cat spinal motoneurons induces a marked loss of synaptic boutons from the cell bodies and dendritic trees. The aim of the present study was to analyze the recovery of synaptic contacts in axotomized motoneurons following reinnervation into muscle. Adult cat spinal motoneurons were first deprived of their muscular contacts for 12 weeks and, then, allowed to reinnervate their target muscle. Two years later, regenerated motoneurons were labeled with horseradish peroxidase to allow quantitative ultrastructural analyses of the synaptic covering of the cell bodies and dendrites. Presynaptic boutons were classified according to their size and the shape of their synaptic vesicles. Results show that a recovery of synaptic covering occurs in the axotomized neurons after muscle reinnervation, but it affects various bouton types to different degrees. The number of S-type boutons synapsing with the soma was 70% higher after reinnervation than at 12 weeks after axotomy, while the number of F-type boutons had increased by only 13%. Compared with the normal situation, the number of S-type boutons synapsing with the proximal dendrites increased from 82% at 12 weeks after axotomy to 180% in the reinnervated state. In conclusion, in adult cat spinal motoneurons, the reestablishment of muscular contact is followed by a normalization of some of the synaptological changes induced by a prolonged state of axotomy. In certain respects restitution is incomplete, but in others it results in overcompensation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002210050653
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  • 34
    Digitale Medien
    Digitale Medien
    Magnetic properties of human liver and brain ferritin (1999)
    Springer
    European biophysics journal 28 (1999), S. 263-267 
    Details
    ISSN: 1432-1017
    Schlagwort(e): Key words Human liver ; Human brain ; Ferritin ; Electron microscopy ; Mössbauer spectroscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Physik
    Notizen: Abstract Human brain (globus pallidus) and liver tissues were investigated by means of electron microscopy (EM), Mössbauer spectroscopy (MS) and SQUID magnetometry techniques. Based on MS measurements, the iron present was identified to be in the ferritin-like form (61–88%) and in the form of a low-spin iron species (the balance). Its overall concentration was estimated as 1.5(3) mg in the brain and 2.4(5) mg in the liver, per gram of lyophilized tissue. The average core diameter was determined by EM measurements to be equal to 7.5(1.3) nm for the liver and 3.3(5) nm for the brain. Magnetization measurements carried out between 5 and 300 K yielded an estimation of an average blocking temperature, KT BL, as equal to 6.7 K and 8.5 K for the liver and the brain, respectively. From the dependence of KT BL on the external magnetic field it was concluded that the ferritin-like cores in the studied samples can be regarded as non-interacting particles. Finally, the uniaxial magnetic anisotropy constant was determined to be 6×103 J/m3 for the liver and 4×104 J/m3 for the brain.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002490050208
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  • 35
    Digitale Medien
    Digitale Medien
    Muscle and skin biopsies are a sensitive diagnostic tool in the diagnosis of CADASIL (1999)
    Springer
    Journal of neurology 246 (1999), S. 526-532 
    Details
    ISSN: 1432-1459
    Schlagwort(e): Key words CADASIL ; Cerebrovascular disease ; Skin biopsy ; Muscle biopsy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a microangiopathic syndrome. Although the defective gene has been identified, genetic analysis may be effort some due to its large size and various mutations. Providing a reliable diagnostic marker would therefore be helpful. Electron microscopy has revealed characteristic electron-dense granular deposits in the basal lamina of vessels of patients with CADASIL. We investigated the sensitivity of skin and muscle biopsies for diagnosing CADASIL. We examined 30 family members of three unrelated German families affected by CADASIL. In 14 of the 21 affected individuals we performed skin and muscle biopsies; two patients were clinically asymptomatic. Under electron microscopy all muscle and skin biopsy specimens showed patches of granular and electron-dense material in the basal layer of both arterioles and capillaries. These findings confirm that general microangiopathy is a typical feature of this syndrome and is present in the early phase of the disease with or without clinical manifestation. Thus, as electron microscopy of skin biopsy specimens can establish the diagnosis of CADASIL with high certainty, it may be considered the method of first choice.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004150050398
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  • 36
    Digitale Medien
    Digitale Medien
    Isolation and characterization of a Clostridium sp. with cinnamoyl esterase activity and unusual cell envelope ultrastructure (1999)
    Springer
    Archives of microbiology 172 (1999), S. 139-149 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Key wordsClostridium xylanolyticum ; Cinnamic acid ; Esterase ; Lignocellulose ; Sporogenesis ; Ultrastructure ; Cell envelope
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Microorganisms that hydrolyse the ester linkages between phenolic acids and polysaccharides in plant cell walls are potential sources of enzymes for the degradation of lignocellulosic waste. An anaerobic, mesophilic, spore-forming, xylanolytic bacterium with high hydroxy cinnamic acid esterase activity was isolated from the gut of the grass-eating termite Tumilitermes pastinator. The bacterium was motile and rod-shaped, stained gram-positive, had an eight-layered cell envelope, and formed endospores. Phylogenetic analysis based on 16S rRNA indicated that the bacterium is closely related to Clostridium xylanolyticum and is grouped with polysaccharolytic strains of clostridia. A wide range of carbohydrates were fermented, and growth was stimulated by either xylan or cellobiose as substrates. The bacterium hydrolysed and then hydrogenated the hydroxy cinnamic acids (ferulic and p-coumaric acids), which are esterified to arabinoxylan in plant cell walls. Three cytoplasmic enzymes with hydroxy cinnamic acid esterase activity were identified using non-denaturing gel electrophoresis. This bacterium possesses an unusual multilayered cell envelope in which both leaflets of the cytoplasmic membrane, the peptidoglycan layer and the S layer are clearly discernible. The fate of all these components was easily followed throughout the endospore formation process. The peptidoglycan component persisted during the entire morphogenesis. It was seen to enter the septum and to pass with the engulfing membranes to surround the prespore. It eventually expanded to form the cortex, verification for the peptidoglycan origin of the cortex. Sporogenic vesicles, which are derived from the cell wall peptidoglycan, were associated with the engulfment process. Spore coat fragments appeared early, in stage II, though spore coat formation was not complete until after cortex formation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002030050753
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  • 37
    Digitale Medien
    Digitale Medien
    Intimal-type primary sarcoma of the aorta (1999)
    Springer
    Virchows Archiv 435 (1999), S. 62-66 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Key words Rhabdomyosarcoma ; Aorta ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  We report an intimal sarcoma presenting as an aortic aneurysm. A 68-year-old man suffered from chest pain and speech disturbance. Computed tomography showed a sacciform aneurysm of the aorta, which was resected, revealing a polypoid tumour measuring 1.5×2×2.5 cm projecting into the lumen. This proved to be a poorly differentiated high-grade sarcoma having morphological, immunophenotypic and ultrastructural features consistent with rhabdomyosarcomatous differentiation. Primary sarcomas of the aorta are extremely rare. Many cases have been diagnosed as ”intimal” on the basis of their site of origin, and they are not easy to classify from their histological pattern. Electron microscopy and the use of a more comprehensive panel of immunohistochemical markers should be applied in the histological classification of ”intimal” sarcoma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004280050396
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  • 38
    Digitale Medien
    Digitale Medien
    Types, numbers and distribution of synapses on the dendritic tree of an identified visual interneuron in the brain of the locust (1999)
    Springer
    Cell & tissue research 296 (1999), S. 645-665 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Descending contralateral movement detector (DCMD) ; Identified neuron ; Vesicles ; Electron microscopy ; 3-D reconstruction ; Locust ; Schistocercagregaria (Insecta)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  The descending contralateral movement detector (DCMD), an identified descending interneuron in the brain of the locust Schistocerca gregaria has been investigated by using light and electron microscopy. We describe the fine structure, distribution and numbers of synapes that it receives from another identified brain neuron, the lobular giant movement detector (LGMD), and from unidentified neurons. The DCMD dendrites emerging from the integrative segment vary in form and number between individuals and sexes but always form a flattened dendritic domain. The arborizations and the integrative segment appear to be exclusively postsynaptic. Two types of synaptic contacts (Type 1 and 2) onto the DCMD can be discerned as having either round (Type 1) or pleiomorphic synaptic vesicles (Type 2) and by large (Type 1) or small (Type 2) subsynaptic appositions. Contact zones of Type 1 synapses are smaller than those of Type 2. LGMD-synapses are of Type 1 and occur intermingled with presynaptic sites of unidentified units. Some branches of the DCMD receiving input from unidentified units are devoid of contacting LGMD processes. Synapses of both types are randomly distributed over the DCMD integrative segment and at fibres with similar sizes.Type 1 synapses are much more frequent than Type 2 synapses and their number is negatively correlated with fibre diameter. For a whole DCMD dendritic arborization, a total of 8500 active zones of chemical synapses has been calculated, including a mininum of 2250 LGMD-synapses and about 1000 Type 2 synapses. The DCMD may thus receive a considerable amount of input from as yet unidentified neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051325
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  • 39
    Digitale Medien
    Digitale Medien
    Metaphase-specific cell death in meiotic spermatocytes in mice (1999)
    Springer
    Cell & tissue research 296 (1999), S. 359-369 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Apoptosis ; Electron microscopy ; Meiosis ; Spermatocytes ; Spermatogenesis ; Testis ; TUNEL ; Mouse (10 strains)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  Apoptosis of male germ cells is a widespread but little-understood phenomenon in many animal species. The elucidation of its mechanisms could be useful in the understanding of male infertility. We have examined the distribution of dying cells with the terminal transferase-mediated nick-end labeling (TUNEL) method and by an electron-microscopic procedure in the testes of 10 mouse strains, viz., C57BL/10 (B10), SL/NiA (SL), C57BL/6 (B6), C3H/He (C3H), BALB/c (BALB), DBA2 (DBA), CBA/J (CBA), MRL/MpJ-+/+ (M+), MRL/MpJ-lpr/lpr (lpr), and wild-type NJL mice (Mus musculus musculus). In the testes of the B10, NJL, SL, B6, C3H, BALB, DBA, and CBA mice, very few TUNEL-positive cells are distributed in the seminiferous tubules, whereas in the testes of the M+ and lpr mice, many TUNEL-positive cells, which are restricted to stage XII seminiferous tubules, have been identified. The most important finding is that many metaphases of meiotic spermatocytes show a marked TUNEL-positive reaction. Some metaphases show apoptotic morphology electron-microscopically. These results suggest that the testes of MRL strains will provide a useful model for the study of the mechanism of metaphase-specific apoptosis in meiotic spermatocytes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051296
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  • 40
    Digitale Medien
    Digitale Medien
    Articular chondrocytes and synoviocytes in a co-culture system: influence on reactive oxygen species-induced cytotoxicity and lipid peroxidation (1999)
    Springer
    Cell & tissue research 296 (1999), S. 555-563 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Chondrocyte ; Synoviocyte ; Co-culture ; Proliferation ; Lipid peroxidation ; Cytotoxicity ; Ultrastructure ; Rat (Wistar)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  Objective: A new co-culture system of rat articular chondrocytes and synoviocytes (HIG-82; cell line) was incubated with phorbol myristate acetate (PMA), H2O2 or a combination of Fe2+ and ascorbic acid to simulate inflammation-like radical attacks in articular joints. Methods: Chondrocytes were characterized by immunocytochemistry against collagen type II, transmission electron (TEM) and light microscopy. Lipid peroxidation was investigated by measuring thiobarbituric-acid-reactive material in the supernatants, cytotoxicity by determining release of lactate dehydrogenase and proliferation by measuring [3H]thymidine incorporation, culture protein and DNA. Results: PMA or Fe2+ and ascorbic acid induced lipid peroxidation in chondrocytes and synoviocytes that was decreased significantly in co-cultures. PMA and H2O2 dose dependently induced release of lactate dehydrogenase in chondrocytes, which was lowered in co-cultures or in previously co-cultured chondrocytes to a nearly basal level. In contrast, conditioned media of synoviocyte cultures showed no lowering effect on the radical-induced toxicity. Protection against H2O2-induced damage of cellular membranes by co-culturing was also shown by TEM. Synoviocytes released chondrocyte-stimulating growth factors spontaneously without previous interaction. Conclusion: Chondrocytes establish protective mechanisms against reactive oxygen species via an interaction with synoviocytes. Our co-culture model presents a possible way to study mechanisms of inflammation in articular joints under defined conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051317
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  • 41
    Digitale Medien
    Digitale Medien
    Ultrastructure and distribution dynamics of chloride cells in tilapia larvae in fresh water and sea water (1999)
    Springer
    Cell & tissue research 297 (1999), S. 119-130 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Chloride cells (mitochondria-rich cells) ; Teleost larvae ; Osmoregulation ; Immunohistochemistry ; Quantification ; Ultrastructure ; Oreochromis mossambicus (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  Integumental and branchial chloride cells of tilapia larvae (Oreochromis mossambicus) were studied at the light-microscopical and ultrastructural level. Total numbers and distribution of chloride cells were quantified after immunostaining of cross sections of the entire larvae with an antibody against the α-subunit of Na+/K+-ATPase. The majority (66%) of Na+/K+-ATPase-immunoreactive (ir) cells, i.e. chloride cells, of freshwater tilapia larvae were located extrabranchially up to 48 h after hatching. Five days after hatching, the majority (80%) of chloride cells were found in the buccal cavity. Transfer of 24-h-old larvae to 20% sea water speeded up this process; 24 h after transfer (i.e. 48 h after hatching), the majority (59%) of chloride cells were located in the buccal cavity. The branchial chloride cell population of 24-h- and 120-h-old larvae consisted of immature, mature, apoptotic and necrotic chloride cells. However, relatively more immature chloride cells were observed in freshwater larvae (42–63%) than in (previously studied) freshwater adults (21%), illustrating the developmental state of the gills. After transfer to sea water, the incidence of degenerative chloride cells did not change. Furthermore, the incidence of immature cells had decreased and a new subtype of chloride cells, the ”mitochondria-poor” cells, appeared more frequently. These mitochondria-poor chloride cells were characterised by an abundant tubular system and relatively few mitochondria, which were aligned at the border or concentrated in one part of the cytoplasm. Most of these cells did not contact the water. The function of their enhanced appearance after seawater transfer is unknown.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051339
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  • 42
    Digitale Medien
    Digitale Medien
    Peripheral synapses at identifiable mechanosensory neurons in the spider Cupiennius salei : synapsin-like immunoreactivity (1999)
    Springer
    Cell & tissue research 295 (1999), S. 13-19 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Mechanoreceptors ; Synaptic proteins ; Histochemistry ; Ultrastructure ; Slit sensilla ; Hair sensilla ; Cupiennius salei (Chelicerata)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Indirect immunocytochemical tests were used at the light- and electron-microscopic levels to investigate peripheral chemical synapses in identified sensory neurons of two types of cuticular mechanosensors in the spider Cupiennius salei Keys.: (1) in the lyriform slit-sense organ VS-3 (comprising 7–8 cuticular slits, each innervated by 2 bipolar sensory neurons) and (2) in tactile hair sensilla (each supplied with 3 bipolar sensory cells). All these neurons are mechanosensitive. Application of a monoclonal antibody against Drosophila synapsin revealed clear punctate immunofluorescence in whole-mount preparations of both mechanoreceptor types. The size and overall distribution of immunoreactive puncta suggested that these were labeled presynaptic sites. Immunofluorescent puncta were 0.5–6.8 μm long and located 0.5–6.6 μm apart from each other. They were concentrated at the initial axon segments of the sensory neurons, while the somata and the dendritic regions showed fewer puncta. Western blot analysis with the same synapsin antibody against samples of spider sensory hypodermis and against samples from the central nervous system revealed a characteristic doublet band at 72 kDa and 75 kDa, corresponding to the apparent molecular mass of synapsin in Drosophila and in mammals. Conventional transmissionelectron-microscopic staining demonstrated that numerous chemical synapses (with at least 2 vesicle types) were present at these mechanosensory neurons and their surrounding glial sheath. The distribution of these synapses corresponded to our immunofluorescence results.Ultrastructural examination of anti-synapsin-stained neurons confirmed that reaction product was associated with synaptic vesicles. We assume that the peripheral synaptic contacts originate from efferents that could exert a complex modulatory influence on mechanosensory activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051208
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  • 43
    Digitale Medien
    Digitale Medien
    Androgen-induced changes in Leydig cell ultrastructure and steroidogenesis in juvenile African catfish, Clarias gariepinus (1999)
    Springer
    Cell & tissue research 297 (1999), S. 291-299 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Teleost fish ; Puberty ; Testes ; Sex steroids ; Ultrastructure ; Steroidogenesis ; Clarias gariepinus (Teleostei)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  The present report focuses on the mechanism(s) involved in the steroid-induced decrease of androgen production in immature African catfish testes that was observed in previous studies. Juvenile animals were implanted with Silastic pellets containing different 11-oxygenated androgens (11-ketotestosterone, KT; 11β- hydroxyandrostenedione, OHA; 11-ketoandrostenedione, KA), testosterone (T) or estradiol-17β (E2). Control groups received steroid-free pellets. Two weeks later, testis tissue fragments were either incubated with increasing concentrations of catfish luteinizing hormone (LH), or incubated with [3H]-pregnenolone ([3H]-P5) or [3H]-androstenedione ([3H]-A). Tissue fragments were also prepared for the quantitative assessment of Leydig cell morphology. Most of the parameters studied were not affected significantly by implantation of E2. Implantation of all androgens inhibited both the basal and the LH-stimulated androgen secretory capacity in vitro. This was associated with a reduced size of the Leydig cells and loss of half of their mitochondria. The studies on the metabolism of tritiated steroid hormones indicated that steroidogenic steps prior to 11β-hydroxylation, probably C17–20 lyase activity, were affected by all androgens. Although the effects of 11-oxygenated androgens and T on Leydig cells were mostly similar, previous work showed that only the 11-oxygenated androgens stimulated spermatogenesis, suggesting that distinct mechanisms of action are used by 11-oxygenated androgens and T. These mechanisms, however, seem to merge on the same target(s) to impair Leydig cell androgen production. Such a negative feedback mechanism may be of relevance in the context of the decline in androgen secretion per milligram testis tissue that accompanies the first wave of spermatogenesis in pubertal African catfish.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051357
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  • 44
    Digitale Medien
    Digitale Medien
    The distribution and ultrastructure of class II MHC-positive cells in human dental pulp (1999)
    Springer
    Cell & tissue research 295 (1999), S. 151-158 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Class II MHC-positive cells ; Human leukocyte antigen-DR ; Dental pulp ; Dendritic cells ; Macrophages ; Ultrastructure ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The distribution and ultrastructure of class II major histocompatibility complex (MHC)-positive cells were investigated in human dental pulp, employing immunohistochemistry using an anti-human leukocyte antigen (HLA)-DR-monoclonal antibody. HLA-DR-immunopositive cells, appearing spindle-like or dendritic in profile, were densely distributed throughout the dental pulp. Under the electron microscope, these cells exhibited various sizes of vesicles containing clear or opaque contents, multivesicular bodies and characteristic fine tubulovesicular structures in their cytoplasm. Some reactive cells possessed coated pits and vesicles including electron-dense materials, indicating an active endocytosis. At the periphery of the pulp tissue, the HLA-DR-immunopositive cells were predominantly situated in the subodontoblastic layer, with some located in the odontoblast layer and/or predentin and extending their cytoplasmic processes into the dentinal tubules. Cell processes of these cells occasionally made contact with several odontoblast processes in the same way as the nerve fibers in the predentin. These cells never contained the typical phagosomes frequently observed in the HLA-DR-immunoreactive macrophages in the subodontoblastic layer and the pulp core. The results suggest that the HLA-DR-immunopositive cells in the odontoblast layer and/or predentin have some regulatory function on the odontoblasts under physiological conditions, in addition to their involvement in the initial defense reaction after tooth injury.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051221
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  • 45
    Digitale Medien
    Digitale Medien
    Effect of high-level oxygen exposure on the peroxidase activity and the neuromelanin-like pigment content of the nerve net in the earthworm, Lumbricus terrestris (1999)
    Springer
    Cell & tissue research 295 (1999), S. 349-354 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Neuromelanin ; Neuron ; Peroxidase ; Oxygen metabolism ; High-definition light microscopy ; Electron microscopy ; Ultrastructure ; Cytochemistry ; Substantia nigra ; Lumbricusterrestris (Annelida)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Histochemical examination of 1-μm tissue sections from the dorsal nerve plexus of the earthworm, Lumbricus terrestris, reveals multiple brown intraneuronal granules. These granules contain material morphologically and histochemically consistent with neuromelanin. When viewed with transmission electron microscopy, these were seen as single membrane-enclosed biphasic granules with diameters of 370–730 nm. Exposure of L. terrestris to high-level environmental oxygen resulted in an increase in the number of neuromelanin-like pigment granules within the neurons of the circular muscle layer. As measured by ortho-phenylenediamine hydrochloride, the endogenous peroxidase activity of extracts from worms incubated in high-level environmental oxygen was 51% more than controls. The endogenous peroxidase activity was localized in situ with 3,3-diaminobenzidine (DAB) and was found to increase in and around the neuromelanin-like pigment-containing neurons within the circular muscle layer. These studies suggest that the nerve net of L. terrestris may serve as a model to study the role of neuromelanin production in oxidative stress and its relationship to endogenous peroxidases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051241
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  • 46
    Digitale Medien
    Digitale Medien
    Op/op mice defective in production of functional colony-stimulating factor-1 lack macrophages in muscularis externa of the small intestine (1999)
    Springer
    Cell & tissue research 295 (1999), S. 485-493 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Immunohistochemistry ; Electron microscopy ; Interstitial cells of Cajal ; F4/80 ; CSF-1 ; Kit-receptor ; Mouse (op/op)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The osteopetrotic (op/op) mutant mouse possesses an inactivating mutation in the colony-stimulating factor-1 (CSF-1) gene, which results in the absence of certain macrophages and in osteopetrosis, following a lack of osteoclasts. Studies of the op/op mouse indicate that CSF-1-dependent tissue macrophages may belong to a trophic and/or scavenger subpopulation, which through their effect on other cell types can significantly affect tissue functions, and that cells which are CSF-1 independent have antigen presentation and immunological functions.We have previously identified a cell system of regularly distributed macrophages in the muscularis externa of the small intestine and wanted to extend these studies to the op/op mouse.The present investigations with light- and electron-microscopic methods using fluorescent dextran, methylene blue and immunohistochemistry (F4/80, anti-kit receptor, anti-CD3, anti-CD45R/B220) show that macrophages are absent from the muscle layers, with only an occasional macrophage present in the subserosa. In the lamina propria and submucosa, macrophage numbers are reduced. In all other respects the muscularis externa appears normal, including normal organization and number of interstitial cells of Cajal. Control and op/op mice both lack cells expressing CD3 (T lymphocytes), CD45R/B220 (B lymphocytes) and mast cells in the muscularis externa. This leaves the muscularis externa macrophages as the most likely source of local cytokine production under such conditions as postoperative ileus and intussusception in infants, where the muscularis externa appears to be one target of cytokines. We conclude that the lack of macrophages, combined with the preservation of otherwise normal structure, will make the op/op mouse a valuable model by which to assess the functions and relative importance of the muscularis externa macrophages in relation to intestinal motility under normal and pathological conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051254
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  • 47
    Digitale Medien
    Digitale Medien
    Survival of rat MCH (melanin-concentrating hormone) neurons in hypothalamus slice culture: histological, pharmacological and molecular studies (1999)
    Springer
    Cell & tissue research 297 (1999), S. 23-33 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Melanin-concentrating hormone neurons ; Lateral hypothalamic slice culture ; Immunocytochemistry ; Ultrastructure ; In situ hybridization ; Competitive RT-PCR ; Leptin assay ; Rat (Sprague Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  Hypothalamic slices containing the lateral hypothalamic area (LHA) were prepared from 6- to 8-day-old rats and maintained in stationary culture for up to 35 days in order to analyse how well the melanin-concentrating hormone (MCH) neurons survived. As previously reported for other brain areas, this method yielded a long-term well-preserved organotypic organization. Light- and electron-microscopic investigations showed that differentiation continued and that synaptic contacts developed in vitro. After a period of elimination of damaged cells and fibres, most of the remaining neurons and glial cells retained a normal morphology throughout the culture period. MCH neurons, in particular, survived well as attested by the strong immunocytochemical and in situ hybridization signals still observed after several weeks. In a comparison with the day of explantation, competitive reverse transcription/polymerase chain reaction demonstrated the remarkable stability of the level of MCH mRNA at least until the 20th day in culture; after 30 days, the clear decrease in this level seemed to be correlated with a loss of MCH neurons, rather than with a decrease in MCH expression. After 10 days of culture, the incubation of slices in the presence of the hormone leptin (50 ng/ml) resulted in a strong decrease of MCH gene expression, suggesting that MCH neurons retained their physiological properties. Thus, the LHA slice stationary culture, especially between one and three weeks (i.e. after tissue stabilization and before extensive cell loss), appears to be a suitable method for physiological and pharmacological studies of these neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051330
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  • 48
    Digitale Medien
    Digitale Medien
    Caveolin and its cellular and subcellular immunolocalisation in lung alveolar epithelium: implications for alveolar epithelial type I cell function (1999)
    Springer
    Cell & tissue research 295 (1999), S. 111-120 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words Caveolin ; Caveolae ; Lung ; Alveolar epithelial type I cell ; Immunocytochemistry ; Electron microscopy ; Confocal laser scanning microscopy ; Rat (CD)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Caveolae are flask-shaped invaginations of the plasmalemma which pinch off to form discrete vesicles within the cell cytoplasm. Biochemically, caveolae may be distinguished by the presence of a protein, caveolin, that is the principal component of filaments constituting their striated cytoplasmic coat. Squamous alveolar epithelial type I (ATI) cells, comprising approximately 95% of the surface area of lung alveolar epithelium, possess numerous plasmalemmal invaginations and cytoplasmic vesicles ultrastructurally indicative of caveolae. However, an ultrastructural appearance does not universally imply the biochemical presence of caveolin. This immunocytochemical study has utilised a novel application of confocal laser scanning and electron microscopy unequivocally to localise caveolin-1 to ATI cells. Further, cytoplasmic vesicles and flask-shaped membrane invaginations in the ATI cell were morphologically identified whose membranes were decorated with anti-caveolin-1 immunogold label. Coexistent with this, however, in both ATI and capillary endothelial cells could be seen membrane invaginations morphologically characteristic of caveolae, but which lacked associated caveolin immunogold label. This could reflect a true biochemical heterogeneity in populations of morphologically similar plasmalemmal invaginations or an antigen threshold requirement for labelling. The cuboidal alveolar epithelial type II cell (ATII) also displayed specific label for caveolin-1 but with no ultrastructural evidence for the formation of caveolae. The biochemical association of caveolin with ATI cell vesicles has broad implications for the assignment and further study of ATI cell function.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051217
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  • 49
    Digitale Medien
    Digitale Medien
    Effects of reserpine on ECL-cell ultrastructure and histamine compartmentalization in the rat stomach (1999)
    Springer
    Cell & tissue research 295 (1999), S. 131-140 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Key words ECL cells ; Gastrin ; Reserpine ; Organelles ; Ultrastructure ; Rat (Sprague-Dawley)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The histamine-storing ECL cells in the stomach play a key role in the control of acid secretion. They contain granules, secretory vesicles and microvesicles, and sustained gastrin stimulation results in the additional formation of vacuoles and lipofuscin bodies. The cells are rich in the vesicle monoamine transporter type-2 (VMAT-2), which can be inhibited by reserpine. The present study examines the effect of reserpine on ECL-cell ultrastructure and histamine compartmentalization. Rats received reserpine and/or gastrin. Reserpine was given twice by the intraperitoneal route (25 mg/kg once daily). Gastrin-17 was given by subcutaneous infusion (5 nmol/kg/h), starting at the time of the first reserpine injection and continuing for 4 days when the rats were killed. At this stage, histamine in the oxyntic mucosa was unaffected by reserpine but elevated by gastrin. Immunocytochemical analysis (confocal microscopy) showed ECL-cell histamine in control and gastrin-treated rats to be localized in cytoplasmic organelles (e.g., secretory vesicles). After treatment with reserpine alone or reserpine+gastrin, ECL-cell histamine occurred mainly in the cytosol. Planimetric analysis (electron microscopy) of ECL cells showed reserpine to increase the number, size and volume density of the granules and to reduce the size and volume density of the secretory vesicles. Gastrin reduced the number and volume density of granules and secretory vesicles, increased the number and volume density of microvesicles and caused vacuoles and lipofuscin bodies to appear. Reserpine+gastrin increased the number, volume density and size of the granules. Reserpine prevented the effects of gastrin on secretory vesicles, vacuoles and microvesicles, but did not prevent the development of lipofuscin. Our findings are in line with the views: (1) that preformed cytosolic histamine is taken up by granules/secretory vesicles via VMAT-2, that histamine is instrumental in the transformation of granules into secretory vesicles and in their consequent enlargement and (2) that vacuoles are formed by the fusion of large secretory vesicles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004410051219
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  • 50
    Digitale Medien
    Digitale Medien
    Structure and function of the human oocyte-cumulus-corona cell complex before and after ovulation (1999)
    Springer
    Protoplasma 206 (1999), S. 270-277 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Cumulus oophorus ; Ovarian follicle ; Fertilization ; Ultrastructure ; Immunocytochemistry ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The fine structure of the human cumulus oophorus has been reviewed on the basis of scanning and transmission electron microscopic observations as well as of immunofluorescence data. Tissues sampled from preovulatory ovarian follicles and cumulus-enclosed oocytes and fertilized eggs (collected from the oviduct or obtained during in vitro fertilization procedures) have been evaluated from a microtopographic and morphodynamic point of view in order to better clarify the possible role of this population of cells. In particular, the following aspects have been studied and discussed: the presence of multiple close contacts (modulated by the interposition of the zona pellucida) between the oocyte surface and the long microvillous evaginations projecting from the inner aspect of corona cells surface (through these structures the intraovarian cumulus oophorus may control oocyte growth and metabolism up until the time of ovulation); the occurrence of different subpopulations of cells (steroid-synthetic cells, cells producing adhesive proteins, leukocytes, macrophages) in the postovulatory, extraovarian cumulus oophorus surrounding oocytes, zygotes and early developing embryos. All these elements found in the cumulus mass may positively act, through their paracrine activities, on the chemical composition of the microenvironment in which fertilization occurs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01288215
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  • 51
    Digitale Medien
    Digitale Medien
    Ultrastructural study of the relationship between generative and vegetative cells inMagnolia ×soulangeana Soul.-Bod. pollen grains (1999)
    Springer
    Protoplasma 206 (1999), S. 87-96 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Plasmalemmic cord ; Pollen grain ; Ultrastructure ; Magnolia ×soulangeana
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary InMagnolia ×soulangeana pollen grains the generative cell (GC) does not become totally free within the vegetative cell (VC), at least until the pollen tube emergence. Due to a deviation in its detachment process from the sporoderm, the opposing ends of the VC plasmalemma do not fuse themselves when the GC moves away from the intine. Consequently, the interplasmalemmic space surrounding the GC does not become isolated but rather maintains continuity with the sporoderm through a complex formation that we have called plasmalemmic cord. The real existence of this formation was confirmed through serial sectioning showing the plasmalemmic cord to consist of the VC plasmalemma. In its initial portion it is occupied by a reasonably accentuated wall ingrowth of the inner layer of the intine (intine 3). In the remainder portion, neither of the cytochemical tests used in this work have revealed the presence of a significant amount of wall material. However, ultrathin sections of samples processed either chemically or by cryofixation showed the existence of an intricate system of tubules and vesicles, some of which are evaginations of the VC plasmalemma. The hypothesis that the plasmalemmic cord may have a role in the complex interactions between the two pollen cells is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01279255
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  • 52
    Digitale Medien
    Digitale Medien
    Anatomical and ultrastructural changes of the floral nectary ofPisum sativum L. during flower development (1999)
    Springer
    Protoplasma 206 (1999), S. 57-72 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Anatomy ; Floral nectary ; Modified stomata ; Phloem ; Pisum sativum ; Stereology ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The floral nectary ofPisum sativum L. is situated on the receptacle at the base of the gynoecium. The gland receives phloem alone which departed the vascular bundles supplying the staminal column. Throughout the nectary, only the companion cells of the phloem exhibited wall ingrowths typical of transfer cells. Modified stomata on the nectary surface served as exits for nectar, but stomatal pores developed well before the commencement of secretion. Furthermore, stomatal pores on the nectary usually closed by occlusion, not by guard-cell movements. Pore occlusion was detected most frequently in post-secretory and secretory glands, and less commonly in pre-secretory nectaries. A quantitative stereological study revealed few changes in nectary fine structure between buds, flowers secreting nectar, and post-secretory flowers. Dissolution of abundant starch grains in plastids of subepidermal secretory cells when secretion commenced suggests that starch is a precursor of nectar carbohydrate production. Throughout nectary development, mitochondria were consistently the most plentiful organelle in both epidermal and subepidermal cells, and in addition to the relative paucity of dictyosomes, endoplasmic reticulum, and their associated vesicles, the evidence suggests that floral nectar secretion inP. sativum is an energy-requiring (eccrine) process, rather that granulocrine.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01279253
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  • 53
    Digitale Medien
    Digitale Medien
    Ultrastructural features of the myocardium of children with dilated cardiomyopathy (1999)
    Springer
    Heart and vessels 14 (1999), S. 52-56 
    Details
    ISSN: 1615-2573
    Schlagwort(e): Endomyocardial biopsy ; Dilated cardiomyopathy ; Children ; Ultrastructure ; Basal lamina layering of capillary
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We analyzed the electron-microscopic features of endomyocardial biopsy from pediatric patients with dilated cardiomyopathy (DCM). The specimens examined were taken from the right ventricle of ten patients aged from 2 to 15 years (mean 9.7 years). Biopsy specimens from eight patients with congenital heart disease (tetralogy of Fallot), aged from 3 to 12 (mean 7.3 years), and ten adult patients with DCM, aged from 32 to 60 (mean 45 years), were also examined. Patients considered to have endocardial fibroelastosis, arrhythmogenic right ventricular cardiomyopathy, specific cardiomyopathy, or coronary heart disease were excluded from this study. Specimens from pediatric patients with DCM showed various degrees of ultrastructural abnormalities of myocytes, including myofibrillar fragmentation, mitochondrial abnormalities, and intracellular edema. The ultrastructurally determined contractility failure index based on the severity of myocardial degeneration at the electronmicroscopic level was 4.9 ± 1.1. This value was significantly higher than that in patients with tetralogy of Fallot (0.9 ± 0.6,P 〈 0.001) but was not significantly different from that in adult patients with DCM (6.1 ± 2.6). The index of pediatric patients with DCM who died within 3 years was high (6.0 ± 0.8). Basal lamina layering of a capillary (BLL) in the myocardium was revealed in 1 of the 10 (10%) pediatric patients with DCM and in 6 of the 10 (60%) adult patients with DCM (P 〈 0.05). No BLL was noted in the patients with tetralogy of Fallot. These findings may be related to the pathogenesis of DCM in children and adults.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02481742
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  • 54
    Digitale Medien
    Digitale Medien
    Distribution and transmission of endosymbiotic microorganisms in the oocytes of the pig louse,Haematopinus suis (L.) (Insecta: Phthiraptera) (1999)
    Springer
    Protoplasma 209 (1999), S. 207-213 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Endosymbiont ; Mycetocyte ; Mycetome ; Oocyte ; Transovarial transmission ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary All anoplurans live symbiotically with prokaryotic microorganisms hosted in specialized cells, termed mycetocytes. In nymphs and males mycetocytes are distributed between midgut epithelial cells. In females, besides the midgut, mycetocytes are found in the reproductive organs where they are located at the base of ovarioles in contact with lateral oviducts. The mycetocyte-associated symbionts are transmitted from one generation to the next transovarially. Here, the results of histological and ultrastructural studies on the distribution and transmission of symbiotic microorganisms within the ovaries of the anopluranHaematopinus suis are presented. Interestingly, during advanced oogenesis (i.e., choriogenesis) of this species all symbionts are localized extracellularly and form a tight mass located at the posterior pole of the oocyte just below the hydropyle. In insects studied so far, such localization of transovarially transmitted microorganisms has been reported only in the closely related speciesHaematopinus eurysternus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01453449
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  • 55
    Digitale Medien
    Digitale Medien
    Phase and aggregation behaviour of double-chain cationic surfactants from the class of N-alkyl-N-alkyl′-N, N-dimethylammonium bromide surfactants (1999)
    Springer
    Colloid & polymer science 277 (1999), S. 856-867 
    Details
    ISSN: 1435-1536
    Schlagwort(e): Key words Double chain surfactants ; Aggregates ; Phase diagrams ; Lamellar phases ; Electron microscopy ; SANS
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Notizen: Abstract We present the phase diagrams and the properties of newly synthesised double-chain cationic N-alkyl-N-alkyl′-N,N-dimethylammonium bromide surfactants [C x C y DMABr (x = 12, 14 and 16; y = 10, 11, 12, 14 and 16)]. All the systems studied form liquid-crystalline lamellar phases but with different morphologies: unilamellar vesicles at low surfactant concentrations, multilamellar vesicles and tubular aggregates for surfactant concentrations between 2 and 10 wt% and at even higher concentrations planar bilayers of surfactant molecules in the classical Lα phase. The phase diagrams were determined with macroscopic and microscopic methods (polarisation microscopy, freeze-fracture transmission electron microscopy, scanning electron microscopy and differential interference contrast microscopy). The properties of the surfactant solutions were determined with differential scanning calorimetry measurements for Krafft point determination and small-angle neutron scattering measurements for interlamellar spacing and bilayer thickness. Finally, conductivity and viscosity measurements for phase characterisation were carried out.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003960050462
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  • 56
    Digitale Medien
    Digitale Medien
    Outbreaks of gastroenteritis caused by SRSVs from 1987 to 1992 in Kyushu, Japan: Four outbreaks associated with oyster consumption (1999)
    Springer
    European journal of epidemiology 15 (1999), S. 175-180 
    Details
    ISSN: 1573-7284
    Schlagwort(e): Electron microscopy ; Epidemiology ; Non-bacterial Gastroenteritis ; Oyster ; Small round structured viruses (SRSVs)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract From 1987 to 1992, 18 outbreaks of acute non-bacterial gastroenteritis occurred in Kyushu district. The most common symptoms were diarrhea, vomiting, nausea and abdominal cramp. Small round structured viruses (SRSVs) were detected in 52 (44.8%) of 116 stool samples from 17 outbreaks by the electron microscopy (EM) method, and a significant increase in the antibody level was noted in 42 (80.7%) of 52 paired serum samples from 12 outbreaks by the immune electron microscopy (IEM) method and in 18 (51.4%) of 35 samples from 8 outbreaks by the western blot (WB) method. However, according to the WB method, antigen-antibody reaction was not observed to reference antigen strips (SRSV-9/Tokyo 86-510, 63kDa) in three of the 8 outbreaks. The detected virus was regarded as an etiologic agent for these outbreaks. In four of 5 outbreaks which appeared associated with eating raw oysters, there was a close relation between SRSV infection and consumption of raw oysters.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1007543924543
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  • 57
    Digitale Medien
    Digitale Medien
    Synthesis of colloids and films of Pr, Er and Yb with nonaqueous solvents (1999)
    Springer
    Colloid & polymer science 277 (1999), S. 164-173 
    Details
    ISSN: 1435-1536
    Schlagwort(e): Keywords Nanostructures ; Thin films ; Vapor deposition ; Electron microscopy ; Optical properties
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Notizen: Abstract Colloidal dispersions of Yb, Er and Pr have been prepared by chemical liquid deposition. The metals were cocondensed at 77 K with 2-methoxyethanol and ethanol to produce solvated metal atoms. The particle size of the dispersions was determined by transmission electron microscopy to range from 52 to 1080 Å; the particles had spherical shapes. After solvent evaporation under vacuum, active solids and amorphous powder were deposited over Cu and Al metal. Dispersion stability, particle size, UV/Vis absorption and zeta potential were studied. The solids prepared by solvent evaporation were characterized by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The films prepared on Al were studied by scanning electron microscopy. The most stable colloid was obtained using 2-methoxyethanol: several concentrations were stable for several months and the zeta potential indicated that this colloid stability is mainly due to solvation effects. FTIR spectroscopy of the solids indicated solvent incorporation in the film. This observation was corroborated by thermal analysis. Information on the thermal stability of the films was obtained by TGA. The UV/Vis absorption spectrum was measured at several concentrations under different conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003960050381
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  • 58
    Digitale Medien
    Digitale Medien
    A comprehensive analysis of selected diagnostic methods with respect to their usefulness in evaluating the biology of neoplastic cells in patients with laryngeal cancer (1999)
    Springer
    European archives of oto-rhino-laryngology and head & neck 256 (1999), S. 306-311 
    Details
    ISSN: 1434-4726
    Schlagwort(e): Key words Laryngeal cancer ; p53 ; Oncoprotein ; Ki67 ; Proliferating cell nuclear antigen (PCNA) ; DNA ploidy ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The difficult and complicated mechanism of cancer development with little knowledge about the biology of existing cancers can lead to a permanent search for new examination techniques to improve the precision of life expectancy in patients and the selection of the most efficient methods of treatment. The aim of this study was to analyze certain prognostic factors, i.e., p53, Ki67, proliferating cell nuclear antigen (PCNA), DNA ploidy and cell proliferating activity, as well as the degree of morphological differentiation and cell maturity evaluated on an ultrastructural level in patients with laryngeal cancers in connection with data obtained from follow-up examinations and the clinical course of the disease. Neoplastic tissue was taken from 120 patients with laryngeal cancers. All underwent surgical treatment, radiotherapy and combined treatment in the Department of Otolaryngology, Karol Marcinkowski University School of Medical Sciences, Poznań, Poland, and the Department of Otolaryngology – Head and Neck Surgery, Haukeland University, Bergen, Norway. Before beginning treatment all patients underwent histological verification of their neoplastic tissues. Histopathological examination proved that the majority of cases (95%) had a squamous cell carcinoma. The occurrence of changes within the lymph nodes of the neck (N) was significantly correlated with T, S, Ki67, metastases to lymph nodes, DNA ploidy, site and surgery performed. The degree of clinical progression (S) was intercorrelated with T, N, p53, Ki67, PCNA, DNA ploidy, site and laryngectomy. The occurrence of oncoprotein p53 in neoplastic cells was measured by the staining degree of their nuclei and was correlated with T, S, DNA ploidy, metastases to lymph nodes, PCNA and site. The degree of staining of neoplastic cells for the nuclear antigen Ki67 was correlated to T, N, G, S, DNA ploidy, metastases to lymph nodes and surgical treatment. The proliferative antigen PCNA in the examined population of patients was intercorrelated with T, p53, Ki67, metastases to lymph nodes and surgical treatment. The results obtained from DNA flow cytometry could be associated with N, G, p53, Ki67 and metastases to lymph nodes. On the basis of the results obtained, the techniques suggested for the morphological and biological evaluation of neoplastic cells in cancer of the larynx should include TNM classification + G + DNA + p53 + Ki67.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004050050252
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  • 59
    Digitale Medien
    Digitale Medien
    Electrophysiological and ultrastructural correlates of cryoinjury in sciatic nerve of the freeze-tolerant wood frog, Rana sylvatica (1999)
    Springer
    Journal of comparative physiology 169 (1999), S. 351-359 
    Details
    ISSN: 1432-136X
    Schlagwort(e): Key words Freeze tolerance ; Sciatic nerve ; Cryoinjury ; Dehydration ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract We investigated function and ultrastructure of sciatic nerves isolated from wood frogs (Rana sylvatica) endemic to the Northwest Territories, Canada, following freezing at −2.5 °C, −5.0 °C, or −7.5 °C. All frogs frozen at −2.5 °C, and most frogs (71%) frozen at −5.0 °C, recovered within 14 h after thawing began; however, frogs did not survive exposure to −7.5 °C. Sciatic nerves isolated from frogs frozen at −7.5 °C were refractory to electrical stimulation, whereas those obtained from frogs surviving exposure to −2.5 °C or −5.0 °C generally exhibited normal characteristics of compound action potentials. Frogs responded to freezing by mobilizing hepatic glycogen reserves to synthesize the cryoprotectant glucose, which increased 20-fold in the liver and 40-fold in the blood. Ultrastructural analyses of nerves harvested from frogs in each treatment group revealed that freezing at −2.5 °C or −5.0 °C had little or no effect on tissue and cellular organization, but that (lethal) exposure to −7.5 °C resulted in marked shrinkage of the axon, degeneration of mitochondria within the axoplasm, and extensive delamination of myelin sheaths of the surrounding Schwann cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003600050231
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  • 60
    Digitale Medien
    Digitale Medien
    Echinococcus granulosus: praziquantel treatment against the metacestode stage (1999)
    Springer
    Parasitology research 85 (1999), S. 999-1006 
    Details
    ISSN: 1432-1955
    Schlagwort(e): Key wordsEchinococcus granulosus ; Praziquantel ; Metacestode ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The efficacy of praziquantel against the metacestode of Echinococcus granulosus was studied by means of in vitro incubations or in vivo experiments. The results of in vitro incubations indicated that the effectiveness of praziquantel was higher when the parasite material comprised cysts from cyst masses than in the case of intact cysts that retained their adventitial layer. Ultrastructural alterations in the germinal layer of collapsed cysts incubated in vitro were detected. The results obtained in mice after 4 months of treatment demonstrated no significant difference between the control and treated groups with regard to the number and wet weight of developed cysts. However, ultrastructural alterations were detected in the cyst tissue that were similar to those described in the in vitro experiment. In contrast, the effect of chemoprophylaxis on the number and the wet weight of developed cysts was extremely significant as compared with the control value, the efficacy being 99.41% and 98.32%, respectively. Moreover, ultrastructural observations of the cyst tissue revealed loss of its integrity, and no intact cyton was observed in the germinal layer of the developed cyst.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004360050672
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  • 61
    Digitale Medien
    Digitale Medien
    Morphology and ultrastructure of the anterior adhesive areas of the capsalid monogenean parasites Benedenia rohdei from the gills and B. lutjani from the pelvic fins of Lutjanus carponotatus (Pisces: Lutjanidae) (1999)
    Springer
    Parasitology research 85 (1999), S. 399-408 
    Details
    ISSN: 1432-1955
    Schlagwort(e): Key words Monogenea ; Capsalidae ; Benedenia rohdei ; B. lutjani ; Ectoparasites ; Lutjanus carponotatus ; Glands ; Ultrastructure ; Adhesion ; Attachment
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The anterior adhesive areas of Benedenia rohdei from the gills and B. lutjani from the pelvic fins of Lutjanuscarponotatus at Heron Island, Australia, were studied using scanning and transmission electron microscopy. All specimens were fixed when detached from host tissue. Both monogenean species have two disc-like anteroventral attachment organs, each of which has an anterolateral adhesive area divided into three adjacent zones by tegument from the ventral surface of the attachment organ. A rod-shaped secretion and a smaller, roughly spherical secretion are associated with the anterior adhesive areas in both species; a third type of secretion occurs anteriorly but outside these adhesive areas. The electron-dense spherical secretory bodies released onto the anterior adhesive zones in these Benedenia spp. are of a single type and differ ultrastructurally from those previously reported in monogeneans living on teleost hosts. A correlation, therefore, between secretion morphology and host type is not supported. No relationship was found between parasite microhabitat and secretion morphology.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004360050566
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  • 62
    Digitale Medien
    Digitale Medien
    Intranuclear inclusions of meningioma associated with abnormal cytoskeletal protein expression (1999)
    Springer
    Brain tumor pathology 16 (1999), S. 86-91 
    Details
    ISSN: 1861-387X
    Schlagwort(e): Meningioma ; Intranuclear inclusion ; Immunohistochemistry ; Ultrastructure ; Intermediate filament
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We describe a case of meningothelial meningioma with a large number of intranuclear inclusions. Morphologically, these are divided into cytoplasmic inclusions and nuclear vacuoles. The cytoplasmic inclusion has a limiting membrane with cell organelles and filaments. Inclusions of this type are generally eosinophilic, like the cytoplasm. However, there are many inclusions that are more eosinophilic than the cytoplasm or that have a ground-glass appearance. Some of them may contain fine or coarse granules. On the other hand, the nuclear vacuole lacks a limiting membrane and appears empty. In most of the inclusions of this type, there is a faintly basophilic substance in the margin. Generally, the cytoplasmic inclusions are as immunopositive as cytoplasm with vimentin, but some of these cytoplasmic inclusions are more reactive. Under the electron microscope, abnormal aggregation of intermediate filaments is recognized in the cytoplasmic inclusions. It is considered that a strong reaction of cytoplasmic inclusions with vimentin immunostaining is due to abnormal aggregation of intermediate filaments. The present study distinctly demonstrates abnormal localization of intermediate filaments in the cytoplasmic inclusions, and it is suggested that the cytoskeleton participates in the evolution of the cytoplasmic inclusions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02478908
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  • 63
    Digitale Medien
    Digitale Medien
    Morphologic alterations in the epithelium of the human oviduct induced by a low dosis gestagen (1977)
    Springer
    Archives of gynecology and obstetrics 223 (1977), S. 269-281 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Oviduct ; Gestagen ; Contraception ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Morphological alterations in the epithelium of the human oviduct related to continuous administration of low dosage lynestrenol were studied in 10 women by electron microscopy. The effect of lynestrenol on the morphology of the tubal epithelium was shown to be time dependent. First the discharge of secretory products from the non-ciliated cells was inhibited. Secondary to this the synthetic activities of the cells were drastically decreased. This inactivation of the tubal epithelium reached its maximum after 6 months. At this time the epithelial cells, particularly the non-ciliated cells were almost devoid of organelles and had an electron transparent cytoplasm. In addition to the action of lynestrenol on the secretory and synthetic activities of the cells a strong ciliogenetic effect could be observed after about 3 months of lynestrenol administration. The ratio of ciliated to non-ciliated cells changed from 1∶1 at the beginning of the treatment to 2.9∶1 after 6 months. This ratio was then maintained and could still be found in patients who had used lynestrenol for 25 and 39 months. In contrast to the persistent effect of lynestrenol on the ciliary apparatus of the cells the synthetic activities and the secretory mechanism were partially restored with long standing use. The importance of the observed changes and their possible participation in the contraceptive action of lynestrenol are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00667367
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  • 64
    Digitale Medien
    Digitale Medien
    Feinstrukturelle Untersuchungen über das Nuclear-Channel-System im menschlichen Endometrium (1977)
    Springer
    Archives of gynecology and obstetrics 223 (1977), S. 195-204 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Electron microscopy ; Human endometrium ; Nucleus ; Nucleolus ; Channel system ; Elektronenmikroskopie ; Menschliches Endometrium ; Nukleus ; Nukleolus ; Channel-System
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Das Nuclear-Channel-System ist eine runde bis ellipsoide Struktur, deren Tubuli querangeschnitten oder längsangeschnitten in eine elektronendichte Matrix eingebettet sind. Das NCS liegt meist der Kernmembran dicht an, die in diesem Bereich Einziehungen aufweist. Gelegentlich ist ein Kontakt der Kernmembran mit der Membran eines Tubulus zu beobachten. Im NCS sind Partikel festzustellen, die den 150 Å großen Partikeln des Nucleolus vergleichbar sind, was auf einen Gehalt des NCS an RNA schließen läßt. In hier vorliegenden Untersuchungen konnte das NCS in Zellkernen endometrialer Drüsenzellen während der mittleren und späten Proliferationsphase beobachtet werden. Diese Befunde sprechen gegen eine zwingende Abhängigkeit des Auftretens des NCS vom Zeitpunkt der Ovulation. Das NCS kann somit nicht als eine für postovulatorisches Endometrium typische Struktur angesehen werden. Offensichtlich bestehen zwischen den hormonellen Faktoren und der Ausbildung des NCS Beziehungen, deren Bedeutung bis heute nicht sicher beurteilt werden kann.
    Notizen: Summary The Nuclear Channel System (NCS) is a distinct endometrial pattern as observed by transmission electron microscopy. The NCS was identified in the present study in cell nuclei of endometrial glands during mid and late proliferation. These observations do not support the concept that the NCS develops at the ovulation, and is therefore not a typical post ovulatory structure. It is suggested that there are relations between hormonal factors and the development of the NCS which are as yet no clarified.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00667389
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  • 65
    Digitale Medien
    Digitale Medien
    Die Dezidualisation der endometrialen Stromazelle (1977)
    Springer
    Archives of gynecology and obstetrics 223 (1977), S. 19-31 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Stromal reticulum cell ; Decidua ; Ultrastructure ; Stroma-Retikulumzelle ; Deziduale Umwandlung ; Feinstruktur
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung In der vorliegenden Arbeit werden die feinstrukturellen Veränderungen der endometrialen Stroma-Retikulumzelle über die prädeziduale Reaktion der späten Sekretionsphase bis hin zur ausdifferenzierten Deziduazelle beschrieben. Bei der dezidualen Umwandlung der Retikulumzellen ändern sich Zellvolumen, Organellensortiment und zwischenzellige Beziehungen. Die Veränderungen sind Ausdruck eines adaptativen Funktionswandels der Zellen. Im Gegensatz zur kontinuierlichen Transformation der Feinstruktur zeigt das zytochemische Verhalten eine in Schüben ablaufende Entwicklung, da die neugewonnenen Enzymmuster jeweils erst nach der funktionellen Reifung ihrer Arbeitsstrukturen erfaßt werden können. Zu den wichtigsten zellspezifischen Leistungen der Deziduazelle und ihrer Vorstadien gehören sekretorische und intermediäre endokrine Aufgaben. Als spezifisches Sekretionsprodukt der Stroma-Retikulum- und Deziduazelle lassen sich präkollagene Fibrillen nachweisen. Für eine Beteiligung der Deziduazelle am Steroidmetabolismus sprechen charakteristische Organellenveränderungen, die im zeitlichen Zusammenhang mit Steroiddehydrogenaseaktivitäten auftreten. Ein auffallender Befund der postovulatorischen Retikulumzelle und der voll entwickelten Dezidua sind spezielle Differenzierungen des Karyoplasma (Karyosome). Äahnliche nukleäre Differenzierungen sind auch von anderen Zellen hormonsensitiver Gewebe bekannt. Sie könnten als sichtbare Manifestation der am genetischen Apparat des Kernes angreifenden Steroidhormonwirkung gedeutet werden.
    Notizen: Summary The fine structural changes of the endometrial stromal cell from late secretory phase up to full developed decidua cell have been investigated by means of electron microscope. During decidual transformation the cell volume, the assortment of cytoplasmic organelles and the mode of intercellular attachments undergo characteristic alterations. These alterations reflect an adaptation on new cellular functions. In contrast to the structural organization, which is transformed continuously, the encymatic cell pattern exerts a step wise gradual transformation, since new encymatic capacities can only arise after their functional structures have been established. To the most important functions of decidua cells and their prestages belong secretory and endocrine activities. Precollagen fibrills represent a specific secretory product of the stroma reticulum cells. The active involvement of the full differentiated decidua cells in steroid metabolism is indicated by characteristic transformations of the cytoplasmic organization concomittantly to the appearance of intracellular steroid dehydrogenase activities. So-called karyosoma could be demonstrated within the nuclei of postovulatory stromal reticulum cells as in decidua cells. Similar nuclear differentiations have been observed in various target cells of steroid hormones. They possibly are structural manifestations of the hormonal interaction with the nuclear DNA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00675080
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  • 66
    Digitale Medien
    Digitale Medien
    Ultrastrukturell-morphometrische Untersuchungen an Leberbiopsien — Der Einfluß von Ovulationshemmern auf die menschliche Leber (1977)
    Springer
    Archives of gynecology and obstetrics 223 (1977), S. 205-211 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Electron microscopy ; Stereology ; Human liver ; Oral contraceptives ; Elektronenmikroskopie ; Stereologie ; Menschliche Leber ; Orale Kontrazeptiva
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es wurden Leberbiopsien von 12 Frauen feinstrukturell-morphometrisch untersucht, die über einen Zeitraum von 2 Monaten bis zu 8 Jahren ein Kombinationspräparat zur hormonellen Antikonzeption eingenommen hatten. Die stereologischen Daten wurden bereits vorher erstellten Basiswerten für normale Lebern (Roessner et al., 1977) gegenübergestellt und auf signifikante Unterschiede hin überprüft (p〈0,001). Eine deutliche Volumenzunahme lysosomaler Zelleinschlüsse pro ml Hepatocyten und eine leichte Cytoplasmavergrößerung bei gleichzeitiger Verkleine-rung der Nuclei kennzeichnen die Veränderungen der Hepatocyten. Alle übrigen ermittelten Parameter lassen den Schluß zu, daß wesentliche Alterationen der Ultrastruktur der menschlichen Leber nach hormoneller Kontrazeption nicht auftreten. Ob damit auch funktionelle Alterationen auszuschließen sind, kann hier nicht beantwortet werden.
    Notizen: Summary Liver biopsies from 12 healthy women were investigated morphometrically — according to the methods of Weibel (1969). All women had taken an oral contraceptive agent during 2 til 76 months. The evaluated stereological datas were compared with base-line datas for normal human liver biopsies, which were elaborated in a previous investigation (Roessner et al., 1977). Statistical analysis was performed on an IBM 360/50 computer system, including F- and student's t-test. In the liver biopsy-specimen from the women, which were on oral contraceptives, the volume-density of lysosomes per ml hepatocytes shows a pronounced, significant (p〈0.001) increase. A moderate increase of cytoplasm is combined with decrease of nuclei-volume. The surface-densities of the rough and smooth endoplasmatic reticulum do not differ significantly from the datas calculated from normal human liver biopsies. All other datas too demonstrate that there are no striking changes in the ultrastructure of human liver, caused by oral contraceptives. Functional alterations however can not be excluded.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00667390
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  • 67
    Digitale Medien
    Digitale Medien
    The ultrastructure of granuloma annulare (1977)
    Springer
    Archives of dermatological research 259 (1977), S. 225-234 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Granuloma annulare ; Necrobiosis of collagen ; Palisading granuloma ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Neun Fälle von Granuloma annulare in verschiedenen Entwicklungsstadien wurden elektronenmikroskopisch untersucht, insbesondere Kollagenveränderungen, das entzündliche Infiltrat und Gefäßalterationen. Die nekrobiotischen Veränderungen des Kollagens bestehen in Auflockerung der Bündel vom Rande her, Schwellung der Fibrillen mit Verlust ihrer Querstreifung, völliger Desintegration des Kollagens und Niederschlägen von mucinösen Substanzen, Fibrin und Glykogen. In 2 Fällen waren sogenannte “filamentöse quergestreifte Aggregationen” (= sog. “long-spacing collagen”) nachweisbar. In späteren Stadien zeigte sich Kollagenneubildung. Im Infiltrat sind vor allem Histiocyten/Makrophagen mit Übergängen zu Epitheloidzellen und Riesenzellen, daneben auch Lymphocyten und später Neutrophile identifizierbar. Gefäßveränderungen bestehen in Endothelschwellung und Basalmembranverdoppelungen. Es besteht ein perivasculäres Infiltrat, jedoch keine echte Vaskulitis. Die Ergebnisse sprechen dafür, daß die Nekrobiose des Kollagens ohne primäre Vaskulitis ein initiales Ereignis bei Granuloma annulare darstellt. Pathogenetisch wird ein Immungeschehen vom verzögerten Typ diskutiert.
    Notizen: Summary Nine cases of granuloma annulare at different stages of development were investigated electron microscopically. Special attention was given to collagen changes, to the cellular infiltrate, and to vascular changes. The necrobiotic changes of the collagen were: loosening of the fibers at the borders of the bundles; swelling and loss of cross-striation of the fibrils; and complete degradation of the collagen, with precipitation of mucinous and fibrin material and of glycogen. In 2 cases “cross-banded filamentous aggregations” were present. In later stages new collagen synthesis occurred. In the infiltrate, histiocytes/macrophages were seen developing into epithelioid and giant cells. In addition, numerous active lymphocytes and, at later stages, some neutrophils were found. Vascular changes consisted of endothelial swelling and duplications of the basal lamina. A perivascular infiltrate was present, but no distinct vasculitis was seen. Our results indicate that the necrobiosis of the collagen without primary vasculitis may be an initial event in granuloma annulare. A delayed hypersensitivity mechanism is discussed with regard to pathogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00561450
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  • 68
    Digitale Medien
    Digitale Medien
    Ultrastructural and microanalytical aspects of developing osteodentin in rat incisors (1977)
    Springer
    Calcified tissue international 24 (1977), S. 215-222 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Mineralization ; Osteodentin ; Intracellular ; Ultrastructure ; Microanalysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Newly formed osteodentin obtained from the anterior extremities of fetal or young rat incisors was observed by means of electron microscopy and electron probe X-ray microanalysis. Cells related to osteodentin formation frequently showed membrane bound intracellular bodies containing varying amounts of fine, needle-shaped crystals, which were identified as apatite. The intracellular clusters of apatite crystals were extruded from the cells through membrane fusion or cellular degeneration. These extracellular clusters seemed to be gradually incorporated into the mineralizing collagenous matrix, which developed around them. Frequent occurrence of dense, dotshaped or filamentous profiles suggested that the dense bodies seen in the perinuclear regions or in the Golgi area were the sites of crystal formation. Energy dispersive X-ray point analysis showed that the intracellular or extracellular apatite clusters contained sulfur in a concentration higher than was present in the mineralizing collagenous matrix. Furthermore, wave dispersive X-ray line analysis showed that the concentration of sulfur was higher in the osteodentin matrix than in the dentin matrix. The sulfur detected is presumed to be contained in acid mucopolysaccharides, which were distributed more heavily in the osteodentin matrix than in the dentin matrix. On the basis of these data, it was concluded that the unique chemical and structural characteristics of the osteodentin result primarily from the incorporation of apatite clusters of intracellular origin and associated acid mucopolysaccharides.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02223319
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  • 69
    Digitale Medien
    Digitale Medien
    Ultrastructural responses of the hypoglossal nucleus to the presence in the tongue of botulinum toxin, a quantitative study (1977)
    Springer
    Experimental brain research 30 (1977), S. 313-321 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rat ; Hypoglossal nucleus ; Botulinum toxin ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural effects of local injection of botulinum toxin into the left half of the tongue of the rat, were studied quantitatively 35 days postoperatively in the left hypoglossal nucleus. The results showed (1) a decrease in somatic and neuropil bouton numbers because of loss of boutons with symmetrical synapses and clear spherical synaptic vesicles, (2) a decrease in the numbers of dendrite profiles in the neuropil, (3) an increase in the proportion of dendrites and boutons with unusual inclusions, suggestive of profile retraction, (4) an increase in the proportion of profiles which were unusually electron-dense, (5) an increase in the amount of astrocyte, and a growth of astrocyte sheaths around bouton-free neurone surfaces, (6) the presence of occasional microglia, and (7) subastrocytic subsurface cisterns. Control rats injected with boiled toxin had no responses except (3) and (4) above, and then only to a modest extent, possibly due to mechanical damage of a few axons or terminals at the time of injection, or to insufficient inactivation of the toxin by boiling. The results were compared with those at 35 days after axotomy, and it was concluded that botulinum toxin, which interrupts neuromuscular transmission, elicits the same responses in the hypoglossal neurones, as does transection of the hypoglossal nerve, even though earlier studies had discovered no glial replication after botulinum toxin, in contrast to axotomy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00237258
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  • 70
    Digitale Medien
    Digitale Medien
    Responses in the hypoglossal nucleus to delayed regeneration of the transected hypoglossal nerve, a quantitative ultrastructural study (1977)
    Springer
    Experimental brain research 29 (1977), S. 219-231 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rat ; Hypoglossal nucleus ; Delayed regeneration ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Electron micrographs of the left hypoglossal nucleus of adult male albino rats were quantitatively analyzed from 9–70 days after allowing the transected left hypoglossal nerve to regenerate after an 84 day delay. Delay was achieved by implanting the proximal stump into already innervated sternomastoid muscle, where no regeneration occurred. Regeneration was then allowed by denervating the sternomastoid. During the regenerative period the initially high number of abnormally electron dense perikarya and dendrites decreased to almost normal values, but no cell removal was seen. This suggested that the degenerate appearance of many profiles after prolonged prevention of regeneration, was reversible. The neuropil bouton and dendrite counts, and the numbers of synapsing boutons per dendrite, increased steadily to normal values from the low values of suppressed regeneration. Somatic bouton frequencies, even though already low, decreased further at 32 days, and later increased but not to normal values. The decrease at 32 days coincided with the loss of many subsurface cisterns, and dispersion of Nissl substance, all suggestive of chromatolysis. Later the subsurface cisterns and Nissl substance returned. It was suggested that the delay of complete recovery of somatic bouton frequencies might be because of lack of sensory information from the denervated muscle into which the hypoglossal nerve was regenerating, or because of abnormally low starting values for the recovery phase. Astrocyte (or, occasionally microglial) sheaths persisted along boutonfree perikaryal surfaces.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00237043
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  • 71
    Digitale Medien
    Digitale Medien
    Unilateral renal hypoplasia with associated venous anomaly and hypertension (1977)
    Springer
    Virchows Archiv 374 (1977), S. 169-182 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Juxtaglomerular apparatus ; Renin ; Kidney ; Congenital abnormalities ; Ultrastructure ; Hypertension ; Renal hypoplasia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A child with unilateral renal hypoplasia, high plasma renin levels and hypertension was found to have large numbers of juxtaglomerular granular cells in the affected kidney. They were seen adjacent to and sometimes in the interior of hyalinized glomeruli or, in loose nests scattered in the interstitium. Ultrastructurally they contained large numbers of crystalline protogranules in the Golgi region and also displayed other features suggestive of hyperactivity. Atrophic tubules, smooth muscle and mast cells were present in considerable numbers. Well-preserved renal cortex remained in the affected kidney with no demonstrable juxtaglomerular granularity. After unilateral nephrectomy the patient became normotensive and plasma renin levels became normal. Thus it appears that the juxtaglomerular cells are able to produce and release renin independent of the structural integrity of the juxtaglomerular apparatus and renal glomerulus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432899
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  • 72
    Digitale Medien
    Digitale Medien
    Hepatocyte giant mitochondria: An almost constant lesion in systemic scleroderma (1977)
    Springer
    Virchows Archiv 374 (1977), S. 215-227 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Ultrastructure ; Liver ; Hepatocyte ; Mitochondria ; Gigantism ; Systemic scleroderma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Liver electron microscopic studies were performed in 14 patients with systemic scleroderma. In 13 of these patients, giant mitochondria were demonstrated in the hepatocytes. This ultrastructal abnormality was present whatever the type and duration of the disease and was also present even when the liver was histologically normal. The mechanism of formation of giant mitochondria in systemic scleroderma is unknown.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00427116
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  • 73
    Digitale Medien
    Digitale Medien
    Giant cell tumor of bone (1977)
    Springer
    Virchows Archiv 376 (1977), S. 299-308 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Giant cell tumor ; Ultrastructure ; Acid phosphatase ; Lysosomes ; Bone tumors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The fine structural localization of acid phosphatase in the different cells in a benign giant cell tumor of bone has been studied. Stromal cells type 1 and 2 (fibroblast-like and macrophage-like, respectively) showed the presence of lead phosphate precipitate following incubation in a Gomori-type lead salt medium only in conventional lysosomes. In the multinucleated giant cells, the final product was deposited over lysosome-like organelles, and also over Golgi cisternae, vesicles, and vacuoles. Furthermore, evidence for presence of acid phosphatase was obtained in smooth-surfaced tubular, sausage-, horse-shoe-, and ring-shaped structures and over digestive vacuoles of autophagic or heterophagic origin. Finally, in these cells, many of the tubular and vacuolar elements located subjacent to areas of the plasma membrane with microvillous specializations (abortive brush borders?) were shown to carry acid phosphatase.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432300
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  • 74
    Digitale Medien
    Digitale Medien
    Chronic megakaryocytic-granulocytic myelosis — An electron microscopic study (1977)
    Springer
    Virchows Archiv 373 (1977), S. 191-211 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Myeloproliferative disorder ; Thrombocytes ; Megakaryocytic-granulocytic myelosis ; Bone marrow biopsy ; Megakaryocyte lineage ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The fine structure of the bone marrow in chronic megakaryocytic-granulocytic myelosis (CMGM) was studied in 5 nontreated patients to investigate possible malignant proliferation of megakaryocytes and the role of megakaryopoiesis in fibrillogenesis, terminating in osteomyelofibrosis. In comparison with normal megakaryopoiesis there is an enormous increase of the megakaryocytic cell line and many immature and atypical forms are seen. Most conspicuous are microforms, nuclear-cytoplasmic disorganization and nuclear inclusions. Asynchrony of maturation causes abnormal thrombocytogenesis with premature detachment of platelets resulting in immature and peculiar giant forms of thrombocytes. Besides megakaryocytes appearing superficially normal the maturation anarchy of many cells is so severe that by analogy with observations in other leukaemic cells these abnormalities are thought to be representative of a malignant growth. Moreover, there is a striking accumulation of microfibrils and single collagen fibres around megakaryoblasts. Since these cells contain all those organelles commonly associated with fibre production the initial step for fibrillogenesis may therefore arise from the megakaryoblasts prior to platelet release, or any fibroblast proliferation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432237
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  • 75
    Digitale Medien
    Digitale Medien
    The endocrine cells of the pancreas and related tumours (1977)
    Springer
    Virchows Archiv 373 (1977), S. 327-352 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Pancreatic endocrine cells ; Insulinomas ; Gastrinomas ; WDHA tumours ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Up to seven endocrine cell types have been identified ultrastructurally in the pancreas, including glucagon A cells, insulin B cells, somatostatin D cells, pancreatic peptide F cells and 5-hydroxytryptamine EC cells. In addition, D1 cells, which have been proposed as the cell type producing VIP and possible P cells of unknown function are seen. Various patterns of endocrine cell differentiation have been found in 20 endocrine pancreatic tumours. Well and poorly differentiated B cells have been identified in 6 insulinomas, diagnostic G cells in 3 out of 7 gastrinomas, D1 and/or F cells in 7 diarrheogenic tumours. Moreover, cells apparently unrelated to the prevalent clinical syndrome have been noted in 8 of the 20 tumours. Granular non diagnostic cells (poorly diagnostic gastrin cells? D1 cells?) were particularly frequent in gastrinomas; agranular or poorly granular cells, either of “active” or “stem cell” type, were present in nearly all tumours, particularly in diarrheogenic tumours, gastrinomas and malignant insulinomas. A cytological classification of pancreatic endocrine tumours is proposed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432532
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  • 76
    Digitale Medien
    Digitale Medien
    Immunohistochemical and electronmicroscopic observations on the local immune response in ulcerative colitis (1977)
    Springer
    Virchows Archiv 374 (1977), S. 271-273 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Ulcerative colitis ; Immunoperoxidase ; Complement demonstration ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Inflammatory cell infiltrates in ulcerative colitis have been investigated by means of the immunoperoxidase method and by electronmicroscopy. Considerable morphological and functional changes of the local plasma cell population have been found. The absolute number of plasma cells is raised with a marked increase of IgG-cells and a relative decrease of IgA-cells. In particular complement (C3) has been demonstrated at the basement membrane of the surface epithelium and between epithelial cells. The significance of these findings, as a local humoral immune response, is briefly considered, with regard to their possible pathogenetic importance in aggravating and perpetuating the disease.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432650
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  • 77
    Digitale Medien
    Digitale Medien
    Immunhistochemical and electron microscope analysis of adenomas of the thyroid gland (1977)
    Springer
    Virchows Archiv 374 (1977), S. 285-301 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Thyroid gland ; Thyroid adenoma ; Ultrastructure ; Immunhistochemistry ; Thyroglobulin ; Lysosomes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Histologic, immunhistochemical and electron microscopic changes in 8 cases of scintigraphically proven autonomous thyroid adenomas are described and compared with non-functioning adenomas. Adenomas with a light microscopic appearance suggesting autonomy show follicles which are mainly small or normal sized and lined by columnar thyroid cells with a partly vacuolated and eosinophilic cytoplasm. Immunhistochemically a high content of thyroglobulin corresponds to the amount of rough endoplasmatic reticulum. Typical ultrastructural criteria are a well developed cytocavitary network, numerous mainly apically localized lysosomes, prominent Golgi fields with sprouting vesicles and autophagic vacuoles. The cell surface is, when compared to non-functioning adenomas, enlared apically by numerous long microvilli and basally by deep infoldings. On contrast to experimentally TSH-stimulated animal thyroids, colloid droplets and pseudopodia are rare. The morphological findings are compared with recent biochemical results and the diagnostic value of electron microscopy is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432652
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  • 78
    Digitale Medien
    Digitale Medien
    Distribution of mucosubstances in adenoid cystic carcinoma (1977)
    Springer
    Virchows Archiv 375 (1977), S. 1-12 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Adenoid cystic carcinoma ; Cylindroma ; Salivary glands ; Mucosubstances ; Cytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The distribution of mucosubstances in adenoid cystic carcinoma was investigated, and an attempt was made to characterize histochemically the various mucosubstances present. For these purposes the high iron diamine technique (HID), as well as the Astra blue, aldehyde fuchsin and Alcian blue staining methods were employed. Alcian blue was further combined with the periodic acid-Schiff (PAS) technique, the Alcian blue being applied at pH levels between 0.5 and 2.5. In addition the effects of neuraminidase and hyaluronidase treatment as well as methylation and acid hydrolysis procedures on the staining qualities were studied. Acidic mucosubstances with varying histochemical properties were present in different structures of the neoplasm. The characteristic pseudocyst, a major structural component of the neoplasm, stained strongly with HID, Astra blue, aldehyde fuchsin and Alcian blue at low pH. These staining reactions were markedly suppressed by hyaluronidase treatment, and are apparently attributable to the presence of chondroitin 4- and/or 6-sulfate. Employing the Alcian blue-critical electrolyte concentration technique, the basophilia of the pseudocysts was suppressed at a concentration of 0.5–0.6 M MgCl2, which might indicate polysaccharides of relatively low degree of sulfation. An additional, non-sulfated acid mucin could also be demonstrated in these structures. In certain duct and gland like structures of the tumours, a change in staining pattern from blue or blue-red to red could be observed after exposure of the sections to neuraminidase and subsequent staining with the Alcian blue (pH 2.5)-PAS sequence. Similar observations were also made when the pH of the Alcian blue was lowered to 1.5–1.0, as well as after acid hydrolysis. These findings afford evidence for the presence of a neuraminidase susceptive sialomucin in certain epithelial secretions of the tumor. At the ultrastructural level the replicated basement lamina of the pseudocysts displayed a strong positive reaction with the PA-CrA-silver staining technique. Furthermore, amorphous material within the lumina of small duct like structures also displayed a positive reaction. The amorphous material of the cystic compartments was less reactive.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430640
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  • 79
    Digitale Medien
    Digitale Medien
    Esthesioneuroblastoma (1977)
    Springer
    Virchows Archiv 375 (1977), S. 123-128 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Esthesioneuroblastoma ; Light microscopy ; Electron microscopy ; Argyrophil reaction ; Formaldehyde-induced fluorescence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of esthesioneuroblastoma was examined by histological, histochemical and electron microscopic techniques. The tumour cells showed an argyrophil reaction with the Grimelius technique and contained cytoplasmic secretory granules, but in contrast to previous reports were devoid of histochemically demonstrable biogenic amines. For routine diagnosis the argyrophil technique may be useful in differentiating this type of tumour from epidermoid carcinoma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428100
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  • 80
    Digitale Medien
    Digitale Medien
    Different types of benign nerve sheath tumors (1977)
    Springer
    Virchows Archiv 375 (1977), S. 197-210 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Neuroma ; Neurofibroma ; Ultrastructure ; Cell-kinetic
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Verschiedene Typen von Nervenscheidentumoren wurden lichtmikroskopisch, elektronenmikroskopisch und autoradiographisch untersucht. Die elektronenmikroskopische quantitative Bestimmung der verschiedenen Zelltypen in den Tumoren ergab bei den Neurinomen eine überwiegende Beteiligung von Schwannschen Zellen (87,1%). Bei den Neurofibromen konnte eine unterschiedlich gro\e Anzahl von Bindegewebszellen nachgewiesen werden. Die diffusen Neurofibrome wiesen im allgemeinen eine Zellpopulation auf, wie man sie auch in normalen peripheren Nerven finden kann. Bei den plexiformen Neurofibromen überwogen die Fibroblasten und bei den argyrophilen Neurofibromen wurde eine hohe Perineuralzellbeteiligung gefunden. Die Proliferationsrate der Tumore in der Autoradiographie war im allgemeinen relativ gering, nur das argyrophile Neurofibrom wies einen deutlich höheren Markierungsindex (9,5%) auf.
    Notizen: Summary In a light-, electronmicroscopic and autoradiographic study different types of nerve sheath tumors were classified. Their cellular population was quantitatively evaluated in the electron microscope. In the neurinoma the predominant cell was found to be the Schwann cell, but in the different types of neurofibromata a variable content of connective tissue cells was noted. The diffuse neurofibromata showed a quantitative cellular composition similar to normal peripheral nerves. In the plexiform neurofibroma a large number of fibroblasts were present and in the argyrophilic neurofibroma high content of perineurial cells was found. In autoradiographic sections the tumors showed in general a low proliferation rate (L.i. 1–3.6%). In the argyrophilic neurofibrom a higher labelling index (9.5%) was found.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01102988
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  • 81
    Digitale Medien
    Digitale Medien
    Ultrastructure of Ewing's tumour (1977)
    Springer
    Virchows Archiv 374 (1977), S. 303-316 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Ewing's tumour ; Ultrastructure ; Histochemistry ; Histogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Tumour tissue surgically excised from 10 patients bearing Ewing's tumour of bones was examined electron microscopically and histoenzymologically. In all cases the tumour was composed of polygonal cells with cytoplasm poor in organelles but with conspicuous aggregates of glycogen particles. There were numerous intercellular connections of desmosomal type and a distinct cell membrane bound positivity for alkaline phosphatase activity. In two cases in which there was a negative reaction for alkaline phosphatase, the lack of enzyme activity might have been related to cytotoxic treatment carried out for several months immediately before excision of the tissue used for histoenzymological studies. The problem of histogenesis of Ewing's tumour remains unresolved although some of the present findings support a haemangiogenic origin of the tumour.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432653
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  • 82
    Digitale Medien
    Digitale Medien
    Target-targetoid phenomenon of the human muscle fibers (1977)
    Springer
    Virchows Archiv 375 (1977), S. 13-22 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Target-targetoid phenomenon ; Histochemistry ; Electron microscopy ; Z-band alteration ; Incomplete innervation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Target and targetoid fibers in a muscle biopsy from a patient with paralysis of the deltoid and supraspinatus muscles were studied by light and electron microscopy. The probable cause of the neuropathy was tumor compression. Target and targetoid change was exclusively confined to hypertrophic or normal-sized fibers. Morphometric evaluation of the target and targetoid fibers showed no significant difference between them. With the electron microscope, up to 4 structural zones were seen in the typical target fiber but many were devoid of either zone 2 (halo) or zone 3, or both. It was conceivable that focal irregularity and streaming of Z-bands were the primary alterations in the process of target-targetoid fiber formation, and that this phenomenon was induced both by partial residual innervation as well as re-innervation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430641
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  • 83
    Digitale Medien
    Digitale Medien
    Spontaneous atherosclerosis: An ultrastructural study in the White Carneau pigeon (1977)
    Springer
    Virchows Archiv 375 (1977), S. 147-157 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Electron microscopy ; Atherosclerosis ; Pigeon
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The atherosclerotic lesions, associated with the celiac intimal smooth muscle cushions, of four and five year old White Carneau pigeons were studied with the light and electron miscroscopes. Light microscopic examination of the spontaneous lesions demonstrated large intimal cushions composed of smooth muscle, abundant collagen, clusters of foam cells and cholesterol crystal clefts. Ultrastructural examination of the intimal atheroma revealed dilatations between apposing endothelial cells which contained a flocculent material, similar to that seen in the subendothelial space. The subendothelial compartment contained abundant collagen, extracellular lipid, vesiculated material and cell processes which contained a flocculent matrix and tubular-like elements. In addition, fibroblast-like interlaminar cells were often observed. Numerous intimal smooth muscle cells were seen which displayed varied morphology. Abundant foam cells were also present within the intimal atheromas. The presence of atherosclerotic lesions in preexisting intimal smooth muscle cushions suggests that hemodynamic factors may be important in the progression of these spontaneous lesions. Endothelial cell dilatations may provide an important route of transport for circulating elements which may accumulate within the subendothelial space. Morphologically, it appears that the smooth muscle cells undergo modification and may represent the precursors of foam cells in this species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428102
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  • 84
    Digitale Medien
    Digitale Medien
    Giant cell tumor of bone (1977)
    Springer
    Virchows Archiv 376 (1977), S. 273-298 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Giant cell tumor ; Ultrastructure ; Bone tumors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We describe here the ultrastructure of the multinucleated giant cells and the mononuclear stromal cells in one case of giant cell tumor of bone. The most frequently occurring stromal cell (“stromal cell type 1”) was of fibroblast-like appearance with an irregular outline of both cells and nuclei. Characteristic features of the cytoplasm were the abundance of rough surfaced endoplasmic reticulum and the well developed Golgi apparatus; particulate glycogen was present in the ground cytoplasm of some cells. A second stromal cell type (“stromal cell type 2”) was also recognized, albeit more infrequently. It was macrophage-like with many mitochondria and lysosomes, but with a poorly developed endoplasmic reticulum. The composition of the fixative was found to influence considerably the appearance of the multinucleated giant cells, especially of their endoplasmic reticulum and Golgi-associated structures. Vacuolar elements with taillike expansions were frequently observed in the vicinity of the Golgi apparatus; their functional significance and relationship to the Golgi apparatus and the endoplasmic reticulum is enigmatic. Bodies with the appearance of conventional lysosomes occurred in limited numbers — while mitochondria were abundant. The structural organization and distribution of the endoplasmic reticulum varied between different regions of the cells. Nuclei were of irregular shape with deep infoldings of their limiting membranes and peripheral condensation of the chromatin. The possible nature of mononuclear cells in the neoplastic process is discussed. The morphologic evidence favors the conclusion that the fibroblast like stromal cell is neoplastic; convincing neoplastic properties are lacking for the type 2 cells. Although similarities exist between multinucleated giant cells and osteoclasts, distinct differences between the two cell types were noted. The origin, function and possible neoplastic nature of the giant cells is discussed on the basis of the findings presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432299
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  • 85
    Digitale Medien
    Digitale Medien
    Morbus Paget des Knochens (1977)
    Springer
    Virchows Archiv 376 (1977), S. 309-328 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Paget's disease ; Osteoclasts ; Ultrastructure ; Cytogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Zur Frage der Cytopathogenese der Riesenosteoclasten beim Morbus Paget des Knochens wurden elektronenmikroskopische Untersuchungen an menschlichen Knochenbiopsien durchgeführt. Anteile von 26 aus diagnostischen Gründen entnommenen Beckenkammbiopsien wurden nach einem besonderen PrÄparationsverfahren unentkalkt für die Elektronenmikroskopie aufgearbeitet. Die Paget-Osteoclasten zeichnen sich durch eine hohe Kernzahl aus. Einzelne Zellkerne besitzen parakristalline Einschlüsse, die Hinweis auf eine Virusinfektion der Zellen sein können. Die Riesenosteoclasten zeigen eine gesteigerte Zellbeweglichkeit und hohe Resorptionsleistung durch Dissektion von Knochenfragmenten aus den endostalen OberflÄchen. Zwischen einkernigen Zellen und Osteoclasten finden sich ultrastrukturell Zellmembraninterdigitationen, die dem Vorgang der Zellfusion entsprechen. Die hÄufige Beobachtung dieser Zellmembrankontakte spricht für eine erhöhte Zellfusionstendenz von einkernigen VorlÄuferzellen der Osteoclasten beim Morbus Paget. Die VorlÄuferzellen stammen aus dem pericapillÄren Bereich und entsprechen morphologisch den Pericyten. Die Annahme einer gesteigerten Zellfusionsrate von einkernigen OsteoclastenvorlÄuferzellen würde die Entwicklung der Riesenosteoclasten erklÄren, die für den Morbus Paget des Knochens typisch sind. Ob diesem Vorgang ein durch Viren ausgelöster cytopathogener Effekt zugrunde liegt, mu\ durch weitere Untersuchungen an den parakristallinen Einschlüssen der Osteoclastenkerne geprüft werden.
    Notizen: Summary The cytogenesis of giant osteoclasts in Paget's disease of bone was studied by means of electron microscopy. 26 iliac crest biopsies were made and divided for light and electron microscopic investigation. A special procedure was used for electron microscopic preparation of bone without previous decalcification. Paget osteoclasts are characterized by their high content of nuclei. Several nuclei may show paracrystalline inclusions pointing to a possible virus infection of these cells. Giant osteoclasts have an increased mobility and a high resorptive activity, manifest by the dissection of bone fragments from endosteal bone surfaces. Cell membrane interdigitations between mononuclear cells and osteoclasts occur as a morphologic concomitant of cell fusion. Frequent occurence of such cell membrane contacts seem to indicate an increased tendency to cell fusion among the mononuclear precursors of Paget-osteoclasts. Precursor cells are located in the pericapillary region, and morphologically resemble pericytes. The assumption of an increased rate of cell fusion amoungst the precursor cells of osteoclasts might explain the development of giant osteoclasts in this disease. Further studies of the paracrystalline nuclear inclusions of Pagetosteoclasts are necessary to determine whether this process can be considered to be a cytopathogenic effect of virus infection.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432301
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  • 86
    Digitale Medien
    Digitale Medien
    Ultrastructure of the liver in a case of childhood cystinosis (1977)
    Springer
    Virchows Archiv 377 (1977), S. 43-48 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Childhood cystinosis ; Liver ; Electron microscopy ; Dark cells ; Tight junctions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ultrastructural findings in the liver in a case of childhood cystinosis are reported. Crystalline structures were found mainly in Kupffer cells. The presence of dark cells, with or without crystals, was the most striking feature observed. Such cells have already been noted within the kidney on one occasion when it was shown that the dark substance was L-cystine (Spear et al., 1971). In this case identical dark material was also found extracellularly. The data shows that free cystine can fill cell cytoplasm and extracellular spaces and the possibility that cystine overproduction may take place in the hyaloplasm should be considered. Extracellular location of cystine in the tubules might account for an increase in epithelial permeability and thus for the Fanconi syndrome.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432697
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  • 87
    Digitale Medien
    Digitale Medien
    The ultrastructure of Rhesus monkey prostate (1977)
    Springer
    Urological research 5 (1977), S. 175-183 
    Details
    ISSN: 1434-0879
    Schlagwort(e): Monkey ; Prostate ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary An ultrastructural study of immature and mature rhesus monkey prostate is described and a comparison is made with human tissue. The immature gland consists of largely undifferentiated epithelium showing little or no secretory activity. The mature gland exhibits the general characteristics of prostates of the other species studied. Columnar epithelial cells and undifferentiated basal cells are observed. The two lobes of the gland show several differences, the caudal lobe being rich in secretory granules, with the cranial lobe consisting of taller vacuolated cells. The description provides a basis for comparison with ultrastructural changes produced during in vivo and in vitro experimentation and with characteristics of normal and diseased human prostate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00263734
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  • 88
    Digitale Medien
    Digitale Medien
    Die Ultrastruktur der Neointima arterieller Gefäßprothesen aus lyophilisierter menschlicher Dura (1977)
    Springer
    Research in experimental medicine 169 (1977), S. 243-251 
    Details
    ISSN: 1433-8580
    Schlagwort(e): Ultrastructure ; arterial prostheses ; lyophilized human dura ; neointima ; Ultrastruktur ; arterielle Gefäßprothesen ; lyophilisierte menschliche Dura ; Neointima
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung 5 aus lyophilisierter menschlicher Dura (LMD) hergestellte und Hunden implantierte Arterienprothesen wurden nach 4, 5 1/2, 13, 43 und 46 Monaten entnommen und elektronenmikroskopisch untersucht. Die Neointima aller Implantate bestand aus Pseudo-Endothelzellen, Fibrozyten und Kollagenfibrillen. 43 und 46 Monate nach Implantation waren außerdem glatte Muskelzellen und elastische Mikrofibrillen in der Neointima vorhanden. Diese entsprach somit in ihrer Zusammensetzung im wesentlichen der Neointima von Kunststoff- und Kollagen-Kunststoff-Arterienprothesen. Die klinische Erprobung von LMD-Implantaten als arterieller Gefäßersatz ist jedoch wegen degenerativer Wandveränderungen in den Prothesen mit fast vierjähriger Verweildauer vorerst noch zu früh.
    Notizen: Summary Five arterial prostheses made of lyophilized human dura (LHD) were inserted into dogs and removed after 4, 5 1/2, 13, 43, and 46 months to be studied with the electron microscope. The neointima of all grafts consisted of pseudo-endothelial cells, fibrocytes, and collagen fibrils. Additionally, 43 and 46 months after implantation smooth muscle cells and elastic microfibrils were present. Thus, the composition of the neointima was substantially identical with that of the neointima of synthetic arterial grafts and collagenfabric ones. The clinical application of arterial prostheses of LHD, however, seems at present too early because of degenerative changes in the walls of those grafts which remained nearly 4 years in the dogs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01852062
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  • 89
    Digitale Medien
    Digitale Medien
    Histological and ultrastructural changes in rat kidney following cadmium injection (1977)
    Springer
    Urological research 5 (1977), S. 15-20 
    Details
    ISSN: 1434-0879
    Schlagwort(e): Cadmium ; Kidney ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cadmium injection in rats affects the genito-urinary system. The renal effects are generally considered to be mainly tubular. Light microscopy of 29 specimens confirms cellular damage in the glomeruli with changes in glomerular capillaries. Electron microscopic changes in the glomeruli confirm changes in the podocytes, thickening of the basement lamina, the occurrence of electron dense deposits in association with the capillary endothelium with platelet and polymorphonuclear cell accumulations which suggests opening of the endothelial junction of the glomerular vessels.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00257111
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  • 90
    Digitale Medien
    Digitale Medien
    Sporulation and spore liberation in Aspergillus fumigatus (1977)
    Springer
    Mycopathologia 60 (1977), S. 175-177 
    Details
    ISSN: 1573-0832
    Schlagwort(e): Aspergillus fumigatus ; Spore formation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00448412
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  • 91
    Digitale Medien
    Digitale Medien
    An ultrastructural survey of the genus Prototheca with special reference to plastids (1977)
    Springer
    Mycopathologia 61 (1977), S. 117-119 
    Details
    ISSN: 1573-0832
    Schlagwort(e): Prototheca ; Colorless alga ; Plastids ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract An ultrastructural investigation of six different species of Prototheca showed that all of them contained starch grains enclosed in double-membrane-bounded structures recognized as plastids. It is concluded that these unicellular species of Prototheca must be considered as non-photosynthetic algae.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00443840
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  • 92
    Digitale Medien
    Digitale Medien
    Population and structure of nerve cells in mouse submandibular ganglion (1977)
    Springer
    Anatomy and embryology 150 (1977), S. 301-312 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Neuron ; Ultrastructure ; Anatomy ; Submandibular ganglion ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The anatomy of the mouse submandibular ganglion, and population and fine structure of nerve cells were studied by light and electron microscopy. The submandibular ganglion is a plexus containing up to forty ganglia along the main and the smaller excretory ducts of the submandibular gland. Measurements of the volume of nerve cell bodies display a pattern of distribution with two main peaks, suggesting the presence of large and small types of the intraganglionic neuron. The large neurons mainly have axo-dendritic synapses in which the postsynaptic element is a small spine-like process, while axo-somatic synapses are more common in the small neurons. In some small neurons nuclear chromatin is unusually conspicuous, and accumulations of vesicles of fairly uniform size occur within the cell body. Decentralized ganglia contain almost no synapses, showing the absence of definite interneurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318348
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  • 93
    Digitale Medien
    Digitale Medien
    The surface ultrastructure of the habenular complex of the rat (1977)
    Springer
    Anatomy and embryology 152 (1977), S. 43-64 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Habenula ; Ependyma ; Supraependymal cells ; Supraependymal axons ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The surface features of the ependymal lining of the habenular complex in rats, aged between three weeks and nine months, were studied by means of scanning and transmission electron microscopy. The ependyma of the medial habenular nucleus is heavily ciliated, the cilia obscuring underlying substructure in SEM — preparations. On the habenular commissure most cilia are arranged in tufts. Cilia are provided with segmental indentations and occasional apical thickenings. Vesicular protrusions of the ependymal cytoplasm into the ventricular lumen and the frequent occurrence of homogeneous supraependymal globules were interpreted as signs of ependymosecretory activity of nucl. hab. med. Supraependymal cells are most numerous on the anterior and superior surface of the habenular commissure. Cells presenting features identical to Kolmer (epiplexus) cells were identified on the ventricular surface of nucl. hab. med. in one specimen showing degenerative changes of undetermined aetiology in the habenular nuclei. It is therefore suggested that such cells need not necessarily be restricted to the choroid plexus. Supraependymal unmyelinated axons are particularly numerous on both nucl. hab. med. and commiss. hab. They make desmosome contacts (maculae adherentes) with the ependymal plasmalemma. Contacts presenting all features of typical synapses were not encountered. The vesicle population of the axonal profiles mainly comprises 35–50 nm translucent round vesicles besides small numbers of 60–100 nm dense-cored vesicles and large pleiomorphic vesicles. Most probably the axons belong to the well-established dense population of serotonergic axons in the dorsal part of the third ventricle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00341434
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  • 94
    Digitale Medien
    Digitale Medien
    An electron microscope study of the differentiating capillaries of the mouse neurohypophysis (1977)
    Springer
    Anatomy and embryology 152 (1977), S. 89-108 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Neurohypophysis ; Capillaries ; Mouse ; Growth and development ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The developing capillaries of the mouse neurohypophysis were studied in the electron microscope to elucidate the fine structural differentiation of the vascular component of the neuro-hemal contact zones in the external median eminence and the neural lobe. In the embryo the growth of the superficial net of the primary plexus of the hypophysial portal system is largely manifested by the presence of proliferation areas located within the capillary plexus covering the surface of the median eminence. Presumptive shallow capillary loops diverge from these areas in the first postnatal week. Differentiation of the capillary wall follows the pattern outlined for continuous capillaries. A few fenestrae appear in the endothelium of immature, superficial vessels at the 17th gestational day, increase in frequency during the following embryonic days, and occur regularly in the postnatal animal. In the neural lobe the internal capillaries proliferate by vascular sprouts emanating from the vessels on the surface of the gland. At the end of embryonic time an extensive net has developed, composed of capillaries with immature characteristics. Proliferation is largely finished by the end of the third postnatal week, when mature capillaries dominate the picture. Formation of attenuated, porous areas is a postnatal process, apart from single fenestrae appearing in the walls of a few immature capillaries in late fetal life. The structural possibilities for an onset of neurohypophysial function in the mouse is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00341437
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  • 95
    Digitale Medien
    Digitale Medien
    Etude ultrastructurale du paraplacenta de chatte: mécanisme de l'érythrophagocytose par la cellule chorionique (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 267-283 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Placenta ; Erythrophagocytosis ; Ultrastructure ; Function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Localisé de part et d'autre du labyrinthe, le paraplacenta ou “bordure brune”, est constitué de la membrane allanto-chorionique faisant face à l'épithélium utérin. Les cellules chorioniques phagocytent et dégradent des hématies d'origine maternelle; cette activité est probablement cyclique. Durant la phase d'“ingestion”, l'hématie est phagocytée à l'apex de la cellule, puis après fusion de lysosomes avec la vacuole phagocytique, la phase “digestive” commence et se déroule principalement dans la zone médiane de la cellule, au niveau de vacuoles de tailles plus réduites. Certaines vacuoles contiennent des figures myéliniques associèes ou non à des granules de taille variable, d'autres un matériel finement granulaire. La brève phase d'élimination se caractérise par la présence au voisinage de la lamelle basale et des capillaires foetaux, de corpuscules de 1,000 Å probablement constitués d'agrégats de particules de ferritine. Ces corpuscules exhibent une activité pseudoperoxydasique. Cette érythrophagocytose placentaire représente la source principale de fer pour le foetus. Les microvilli, les vésicules de micropinocytose, le système tubulaire et les corps multivésiculaires de la zone apicale de la cellule, suggèrent une fonction d'absorption de protéines de la cellule. Il en est de même de la richesse du “cell coat” de la surface membranaire apicale.
    Notizen: Summary Located on all sides of the placental labyrinth, the paraplacenta or “brown border” is constituted by the chorioallantoic membrane and the uterine mucosa facing it. The chorionic cells are actively engaged in the uptake and subsequent breakdown of extravased maternal erythrocytes. This phagocytic activity is probably cyclic in nature. In the “ingestion” phase an erythrocyte is phagocytosed in the apex of a chorionic cell, and the “digestive” phase occurs after fusion of lysosomes with the phagocytic vacuole. Subsequent breakdown of the red cell membrane leads to release of the content of the erythrocyte into the vacuole. Then the breakdown proceeds in smaller vacuoles of the median zone of the cell. Some vacuoles contain concentric whorls of membrane, associated with granules of variable size; others contain a finely granular material. The short-lived final, or “elimination,” phase is characterized by the presence of 1,000 Å finely granular bodies along the basement membrane and in close approximation to fetal capillaries. These non-membrane-bound bodies seem to be constituted of ferritinlike particles and exhibit pseudoperoxydasic activities with D.A.B. procedures. This paraplacental erythrophagocytosis is the major source of iron for the fetus. At their apical surface, the chorionic cells exhibit microvilli, micropinocytotic vesicles and a well-defined “cell coat.” The underlying cytoplasm contains numerous absorption vesicles or tubules and multivesicular bodies suggestive of protein absorption.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318930
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  • 96
    Digitale Medien
    Digitale Medien
    An electron microscopic study of the developing caudate nucleus in euthyroid and hypothyroid states (1977)
    Springer
    Anatomy and embryology 150 (1977), S. 335-364 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Caudate nucleus ; Hypothyroidism ; Development ; Electron microscopy ; synaptogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Thyroid hormone exerts a powerful influence on CNS growth and maturation. Hypothyroidism early in life has long been known to cause disturbances in innate behavior, motor performance, severe and frequently irreversible mental retardation. In this deficiency, depressed caudate neurogenesis, cell migration and neuropil development during the rapid period of CNS growth may contribute to the clinical picture of perceptual handicaps often seen in cretins. Light microscopic and Golgi studies of the developing caudate nucleus in thyroid deficiency have been carried out to help attain insights into the mechanisms whereby the extrapyramidal system regulates motor function. The ultrastructural study of caudate nuclear cytogenesis and synaptogenesis in normal and hypothyroid states provides more detailed information for further analysis of the problem. Hypothyroidism was induced from birth by adding propylthiouracil to the food and drinking water of lactating dams. Linear development of the caudate nucleus of both normal and hypothyroid rats at ages 8, 14, 20, 30 and 42 days was studied by electron microscopy. Thyroid glands were examined by light microscopy to assess the normal and deficient states. Immature cells, primitive processes and synapses were the characteristic features of the 8-day-old normal caudate nucleus. Distinctively wide cisternae of the rough endoplasmic reticulum, loosely packed Golgi apparatus and chromatin clumps throughout the nuclei of the neurons were significant early morphologic variations. The dramatic cytoarchitectural maturation in the 14- and 20-day normal caudate neuropil points to the rapidity of developmental rate. After the growth spurt of the first three weeks a maturational plateau occurs which is characterized by well-formed neuronal cytoplasmic organelles, myelinated and non-myelinated axons, axon terminals, dendrites and their spines, and synapses. Thyroid deficiency causes a marked maturational delay of approximately 7 days in caudate neuronal proliferation, the elaboration of neuronal networks and the attainment of mature synaptic contents and membranes. This delay is evidenced by comparison of the structural similarities between 8-day-old normal and 14-day-old deficient rats; and additional comparisons between the 14-day-old normal and 20-day-old hypothyroid rats. A rapid “catch up” process in fine structural morphogenesis takes place in the period between days 14 and 30 in the deficient animals. Repression of thyroid function does not entirely prevent development of the caudate nucleus but allows a fairly extensive, though critically incomplete degree of maturation. This imperfection is manifested by a decrease in the number of synaptic contacts that persists even after the rapid “catch up” phenomenon of caudate synaptogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318351
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  • 97
    Digitale Medien
    Digitale Medien
    Absorption of horseradish peroxidase by the principal cells of the large intestines of postnatal developing rats (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 53-62 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Large intestine ; Intestinal absorption ; Postnatal development ; Rat ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The absorption of horseradish peroxidase in the rat large intestine during the postnatal developing period was investigated by cytochemical and ultrastructural methods. In the ceca and ascending colons from 4-, and 5-day-old rats, intraluminaly injected peroxidase became localised on microvilli, in the intracytoplasmic network of the apical tubules and small vacuoles (tubulo-vacuolar system), in the large supranuclear vacuole, in the Golgi apparatus, on the lateral and basal cell membranes of the surface principal cells, and also in the lumen of blood capillaries in the subjacent propria. On the other hand, the protein tracer was not seen in the large intestinal epithelial cells that lack tubulo-vacuolar systems and large supranuclear vacuoles within their cytoplasm. In the descending colons of rats of any postnatal age, the epithelial principal cells are devoid of these membrane systems, and exogenous peroxidase was not detected in the cytoplasm of the principal cells. It is assumed that at least the proximal portion of the large intestine in neonatal animals has the capacity to absorb macromolecular protein through those surface principal cells that have specialized intracellular membrane systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315297
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  • 98
    Digitale Medien
    Digitale Medien
    Interaction between mesenchymal cells and the posterior iris epithelium in chicken embryos (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 109-118 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Iris ; Mesenchymal cells ; Chicken embryo ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The iris anlage of 3–10 day old chicken embryos was studied by both light and electron microscopy. Serial semithin sections showed that some of the mesenchymal cells overlying the eye cup moved into the primitive eye cavity by the 3rd day of incubation. On the 4th day some of these cells came into close contact with the basement membrane of the dorsal iris epithelium. The bases of the epithelial cells were flat at this stage. Towards the 10th day they formed cytoplasmic processes which did not penetrate the basement membrane. Fine mesenchymal cytoplasmic processes and a large number of extracellular fibrils developed in the epithelial-mesenchymal interface. The fine mesenchymal processes came into close contact with the basement membrane of the posterior iris epithelium but did not penetrate it. Collagen-like material was observed within the cisternae of the rough ER of the mesenchymal cells at certain stages of development. Both, the mesenchymal cells and the collagen fibrils adjacent to the posterior iris layer disappeared by the 10th day when the entire iris epithelium was completely pigmented. The possible origin of the collagen fibrils and the differentiation of the posterior iris epithelium are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315303
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  • 99
    Digitale Medien
    Digitale Medien
    Primary 9+0 cilia in the embryonic and the adult human heart (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 127-139 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Cilia ; Human heart ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Primary 9+0 cilia have been found in the embryonic and the adult human heart. Proximally the cilia show the typical (+0 filament arrangement. Rearrangement of the filaments occur in their distal regions. The cilia are usually found in deep invaginations of the cell membrane, but can also be found in a superficial position. Close connections are frequently found between cilia and thin cytoplasmic extensions from neighbouring cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00297476
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  • 100
    Digitale Medien
    Digitale Medien
    Placodes of the chick embryo studied by SEM (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 97-108 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Chick embryo ; Placode ; Electron microscopy ; Invagination ; Midbody
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The otic, the lens and the nasal placodes have been examined in chick embryos between stages 10 and 18 of Hamburger and Hamilton. At the stage when each placode first becomes visible conspicuous differences have been seen in the surface morphology between those cells which will invaginate and form the placode and those which will remain on the surface of the head, forming the epidermis. The differences become more pronounced with increasing development. The placode cells possess many surface projections whilst the epidermal cells do not. These differences in surface morphology are related to other differences which are visible in TEM sections, the placode cells being highly columnar and extending the full depth of the placode, whilst the epidermal cells are cuboidal or even squamous. This modification in cell shape of the placode cells is correlated with the presence of longitudinally orientated microtubules. The mechanism of invagination is discussed and evidence is presented which supports the idea that there is a migration of cells into the placode from one side. Such a phenomenon would help to explain the asymmetrical structure of the placode, including the presence of the overhanging lip.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315302
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