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  • 1985-1989
  • 1975-1979  (126)
  • 1925-1929
  • 1978  (126)
  • Electron microscopy  (126)
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 377 (1978), S. 129-144 
    ISSN: 1432-2307
    Schlagwort(e): Nephropathia epidemica ; Hemorrhagic fever ; Glomerular changes ; Immune complex disease ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Electron microscopical changes in the glomeruli in 20 kidney biopsies from 18 patients, who were suffering from or had lately suffered from Nephropathia epidemica were studied. Various kinds of deposits were seen. Under the endothelial cells there were collections of light flocculent material. Small dark deposits were seen in the mesangium at the mesangial cell processes, inside the thickened basement membrane, and occasionally on the epithelial side of the membrane. Large deposits were seen around mesangial cells in the mesangium. Deposits were less numerous than in chronic immune complex diseases. The intramembranous or subepithelial deposits were associated with “moon craters”, membranous convoluted structures or membrane debris. Granular extracellular mesangial material, round extracellular particles and intraendothelial microtubular inclusions were occasionally seen. In two of our cases occasional capsular epithelial cells showed numerous myelin bodies. Typical viruses were not seen in the glomeruli. The findings are in accord with the short period of scanty immune complex deposition in the glomeruli in the clinically active phase of Nephropathia epidemica.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 378 (1978), S. 55-65 
    ISSN: 1432-2307
    Schlagwort(e): Pituitary adenoma ; Acromegaly ; Hormone secretion ; Electron microscopy ; Immunologic techniques
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ultrastructural examination of 184 pituitary adenomas demonstrated the presence of extracellular accumulations of electron dense material in 3 out of 64 cases with acromegaly. Fibrillary structures were seen in larger deposits of such material. This material was only observed in biopsies fixed directly with osmium tetroxide; initial fixation with glutaraldehyde did not retain the material and left empty spaces. Positive immuno-histochemical reaction with specific antibodies demonstrated that the extracellular material contained growth hormone (GH). The presence of this extracellular material could not be related to the age or sex of the patient nor to the duration of symptoms, size of the tumor, presence of diabetes mellitus, or concomitant secretion of prolactin. The pericapillary fibrous sheath was heavily thickened in the patient with the longest duration of symptoms, intermediate in thickness in the second and normal in the third.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 379 (1978), S. 73-83 
    ISSN: 1432-2307
    Schlagwort(e): Neurofibrome ; Tactile-like corpuscles ; Perineurial cell ; Neuroectodermal origin ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In neurofibromas type I (plexiform) and type II (diffuse) the Schwann cell is the predominant cell in the neoplastic proliferation. Electron microscopic investigation of a neurofibroma with structures resembling tactile corpuscles (type III) revealed neoplastic proliferation of perineurial instead of Schwann cells. The tactile-like (pseudo-Meissnerian) corpuscles (corpuscules neurofibromateux) are formed by neoplastic perineurial cells. These cells have a tendency to wrap themselves around longitudinal structures, such as collagen fibres or axons, and to come into direct contact with the latter. This close relationship between the axon and the neoplastic perineurial cell, analogous to that between axon and Schwann cell, points to a neuroectodermal origin of the perineurial cell. The electron microscopic appearances suggest that either the Schwann cell or the perineurial cell is the essential neoplastic component of neurofibromas, the fibroblastic proliferation being a secondary phenomenon.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 381 (1978), S. 1-11 
    ISSN: 1432-2307
    Schlagwort(e): Central neuroblastoma ; Electron microscopy ; Growth cone ; Primitive neural crest ; Neuronal cytogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A cerebral neuroblastoma removed surgically from a female child is presented. Electron microscopy showed numerous neuronal processes with growth cones which are a feature of the developing neurone. In addition there were some rosettes with distinct lumina. The luminal surfaces were covered with a smooth plasma membrane lacking any surface differentiation and the lateral surface of these cells had many cell junctions (terminal bars), reminiscent of a primitive neural tube. These features in a nerve cell tumor help to substantiate it as a neuroblastoma arising from immature rather than differentiated cells. The nature of this rare tumor is discussed.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 378 (1978), S. 75-90 
    ISSN: 1432-2307
    Schlagwort(e): Morbus Fabry ; Electron microscopy ; Freeze-fracturing ; Heterozygotic women ; Homozygotic men
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es werden elektronenmikroskopische Beobachtungen zur Lokalisation und zur Feinstruktur der Glykolipideinschlüsse in verschiedenen inneren Organen bei Morbus Fabry berichtet. Die intrazellulÄren und extrazellulÄren Einschlüsse bestehen aus vielschichtig lamellÄren Membransystemen in konzentrischer und exzentrischer sowie in stapeiförmiger paralleler Anordnung. Diese lamellÄre Anordnung ist charakteristisch für flüssigkristalline Phasen von Phospholipid-Wasser-Systemen. Erstmalig werden ultrastrukturelle Befunde an den inneren Organen einer erkrankten Frau mitgeteilt. Demzufolge lassen sich bei heterozygoten Frauen gleiche Glykolipidablagerungen wie bei homozygoten MÄnnern nachweisen. Die Beziehung der Glykolipideinschlüsse zu den Lysosomen wird erörtert.
    Notizen: Summary Electron microscopic findings are reported on the localization and fine structure of glycolipid inclusions in different organs (heart, kidney, lymph nodes, arterial blood vessels, pancreas) in Fabry's disease in a female. The intracellular and extracellular inclusions were made up of multilamellar membraneous systems in concentric, excentric, and parallel arrangement. This fine structure is characteristic of liquid-crystalline phases of phospholipid-water systems. The same type of inclusions are found in the internal organs of heterozygotic women as in homozygotic men. The relationship between the glycolipid inclusions and the lysosomes is discussed.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 377 (1978), S. 287-300 
    ISSN: 1432-2307
    Schlagwort(e): Megacolon ; Large intestine ; Endocrine cells ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The large intestine resected from 6 Hirschsprung's patients and surgical colonic biopsies from 6 control children were examined with light and electron microscopy. The presence and the relative distribution of various endocrine cell types in both groups of mucosa were determined. In light microscope studies endocrine cell data were expressed as number of cells per unit area of mucosa using a quantitative method after argentaffin and Grimelius's argyrophilic techniques and an immunoperoxidase reaction with glucagon and somatostatin (SRIF) antisera. The results indicate that endocrine cells are apparently not involved in Hirschsprung's disease, since their number and frequency did not differ significantly between the ganglionic and aganglionic segments of Hirschsprung's patients nor between the latter and control children. Glucagon immunoreactive cells were, on the average, 5–6 times and 7–9 times more numerous that SRIF cells in the rectum and the sigmoid, respectively. Ultrastructurally, five endocrine cell types could be distinguished. The fifth type, probably a transition type, apparently disappears in adults.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 380 (1978), S. 31-48 
    ISSN: 1432-2307
    Schlagwort(e): Human liver ; Acute alcoholic hepatitis ; Histoenzymology ; Electron microscopy ; Alcoholic cirrhosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The interpretation of the morphological features of alcoholic hepatitis is discussed in terms of a comparison with the results of an ultrastructural and histoenzymological study of the liver biopsies of nine patients. In these patients liver biopsies were performed in the initial stage of the illness and fifteen days after five were re-biopsied, when the clinical and biological signs were improved. The correlations between morphological and biological data were good, especially for the levels of serological and histoenzymological alkaline phosphatase and gamma-glutamyltranspeptidase evaluations. However, when histological appearances had returned to normal, after two weeks of abstinence from alcohol several histological and ultrastructural features of the initial hepatitis persisted. The presence of evolving cirrhosis was a contributing factor to the severity of the changes seen. Morphologically, apart from the changes due to chronic alcoholic intoxication (steatosis, mitochondrial alteration), the hepatitic lesions comprise Mallory's bodies, cytoplasmic oedema and mitochondrial swelling. Cholestasis was invariably present. Histo-enzymologically there was a reduction in ATPase activity suggesting a metabolic failure in the energy producing pathways. In addition, in the periphery of lobules an active cirrhotic process was present, with tubular de-differentiation of hepatocytes and an increase in gamma-glutamyltranspeptidase on the cytoplasmic membrane. Because of the absence of any topographical relationship between hepatitis and cirrhosis, the presence of lymphocytes in the neighbourhood of the ductules suggested an indirect relationship between both processes, perhaps an autoimmune response initiated by Mallory's bodies.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 380 (1978), S. 317-325 
    ISSN: 1432-2307
    Schlagwort(e): Meningioma ; Psammoma bodies ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Psammoma bodies from eight meningiomas have been examined by both light and scanning electron microscopy (SEM). The bodies are primarily composed of calcium apatite which is deposited within a nidus of tightly laminated collagen fibers.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-2307
    Schlagwort(e): Limb bud cultures (mouse) ; Electron microscopy ; Effect of highly sulfated GAG (SP54® and Arteparon®) ; Collagen structure ; Cartilage pattern
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Addition of 1 mg/ml or higher doses of the highly sulfated pentosanpolysulfoester SP54® or the mucopolysaccharidepolysulfoester Arteparon® to limb bud cultures from 11-day-old mouse embryos caused a marked reduction in the growth of the distal parts of the cartilage anlagen. The most striking effect, however, was the change in the collagen structure of the cartilaginous intercellular substance. After more than 0.05 mg/ml SP54® or Arteparon® no collagen filaments were seen but collagen aggregates with an altered cross-striation occurred. They were produced by an antiparallel arrangement of collagen molecules caused by the highly sulfated substances. By immunofluorescence microscopy it was shown that SP54® and Arteparon® did not influence the distribution of the collagen types but only affected the aggregation of collagen type II. From the morphological point of view the production of endogenous PG seemed to be uneffected by SP54® and Arteparon®. The effect of SP54® and Arteparon® was reversible. After removal of these substances characteristic collagen filaments re-formed. The collagen aggregates were decomposed extracellularly or phagocytosed by chondroblasts and decomposed intracellularly.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 378 (1978), S. 181-197 
    ISSN: 1432-2307
    Schlagwort(e): Axonal swelling ; Spheroid ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Axonal swellings and spheroids in various human diseases were studied by light and electron microscopy. 4 cases of infantile neuroaxonal dystrophy, 2 of degenerative diseases, 2 brain tumors and 3 of cerebrovascular disease were examined. Ultrastructurally most spheroids in infantile neuroaxonal dystrophy consisted of interconnected tubules, stacked membranotubular profiles, alternating layered membranes and accumulations of neurofilaments. Combinations of these four constituents were seen only in infantile neuroaxonal dystrophy. “Torpedos” (fusiform swelling of the axon of a Purkinje cell) consisted exclusively of neurofilaments. Spheroids in case 6 (mental retardation) and 7 (atypical teratoma) consisted of interwoven skeins of neurofilaments and grouped mitochondria. Spheroids in case 8 (demyelination) and 9 (cerebrovascular disease) consisted of packed complex bodies and mitochondria. Spheroids in cases 10 and 11 (cerebrovascular disease) consisted of degenerating organelles only. The morphological differences between cases 9, 10 and 11 probably depends on the severity and timing of the cerebral injury. Most spheroids show similar histological and histochemical properties, but ultrastructural study may give some clue to the origin of the bodies.
    Materialart: Digitale Medien
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  • 11
    ISSN: 1432-2307
    Schlagwort(e): Human parathyroid adenomas ; Electron microscopy ; Parathyroid hormone release ; PTH radioimmunoassay ; Pathophysiology of primary hyperparathyroidism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Twelve parathyroid chief cell adenomas from patients with primary hyperparathyroidism were incubated in a tissue culture system in the presence of different calcium concentrations and for various time periods. The endocrine response of the tissue was examined electron microscopically and radioimmunologically. After incubation in a medium of low calcium concentration the parathyroid adenomas showed ultrastructural signs of stimulation with proliferation of the hormone-synthesizing organelles. The development of the ultrastructural response could first be observed after four hours and increased up to several days. Radioimmunologically, an increase of the hormone secretion could be demonstrated. Converse results were obtained after incubation of the tumor tissue under suppressive culture conditions. To check for de-novo synthesis of the hormone released the tissue was incubated in a 75Se-methionine-containing medium. This resulted in radioactivity of the secreted parathyroid hormone, indicating de novo synthesis in our culture system. The biological potency of the released hormone was demonstrated by comparison of the PTH out of the medium with the international human MRC standard using two different radioassays.
    Materialart: Digitale Medien
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 378 (1978), S. 347-359 
    ISSN: 1432-2307
    Schlagwort(e): Hyaline cartilage ; Proteoglycans ; Glycogen ; Matrix degeneration ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Hyaline cartilage of the talus of a diastrophic dwarf was studied by light and transmission electron microscopy before and after proteoglycan extraction or digestion, glycogen digestion, and enzyme marking. The nuclei of the chondrocytes were as a rule large and round and the cytoplasm contained large vacuoles. Best's carmine stained the cytoplasm of most cells red; after diastase digestion the cytoplasm remained unstained. This suggested that the cells contained glycogen. This observation was complimented by the ultrastructural demonstration of large amounts of glycogen. Cell scars were frequent. The shape and state of activity of the cells as well as the development of intracytoplasmic organelles showed great variability. The matrix showed many areas of degeneration and a general dearth of sulphated acid mucopolysaccharides. A lacey pattern of unmasked collagen fibers was frequently seen. Collagen fibers showed a great variability in diameter and often appeared frayed when examined by electron microscopy. These observations suggest an enzymatic deficiency in chondrocyte mucopolysaccharide and glucose metabolism. The techniques we used when added to biochemical studies should prove useful in the investigation of human dwarfism.
    Materialart: Digitale Medien
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 379 (1978), S. 25-33 
    ISSN: 1432-2307
    Schlagwort(e): Electron microscopy ; Microfilaments ; Microtubules ; Nuclear pockets ; Smooth muscle tumours
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Samples of gastric leiomyosarcomas from two male patients (69 years and 57 years of age) were studied by electron microscopy. The tumour cells contained abundant 50–90 å thick microfilaments and microtubules. Another cell type, regarded as immature leiomyosarcoma cell, contained numerous profiles of granular endoplasmic reticulum, free ribosomes and a well developed Golgi apparatus. There were intercellular junctions of zonula adherens-type between adjacent tumour cells. It was concluded that electron microscopy offers a valuable aid in the diagnosis of gastric neoplasms of smooth muscle origin.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 379 (1978), S. 85-97 
    ISSN: 1432-2307
    Schlagwort(e): Bronchial carcinoid ; Oncocytoma ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We describe a bronchial tumor with a biphasic pattern. The main cellular population is composed of large cells with eosinophilic cytoplasm packed with mitochondria. These oncocytes countain few dense-core membrane limited granules. The secondary cell population has the morphological and histochemical features that characterize the typical bronchial carcinoid. A third cell type, recognizable at ultrastructural level, contains numerous neurosecretory granules and abundant large mitochondria, seeming therefore to represent a transitional cell form. We assume that oncocytes and carcinoid cells, found in the same tumor with intermediate forms, represent the extremes of a morphological spectrum. Furthermore, the oncocytic cytoplasmic components (neurosecretory granules and the mitochondria) are present in reciprocal arrangement in the carcinoid cells. These observations, together with similar reported cases suggest that the oncocytic state corresponds to a functional stage. We consider that oncocytes from this endobronchial tumor and from similar pathologic conditions reported in the literature correspond to carcinoid cells with mitochondrial hyperplasia and with diminished endocrine activity. This oncocytic carcinoid tumor is associated, in the same pulmonary lobe, with a second neoplasm that has the histological and ultrastructural features of a poorly differentiated carcinoid (oat-cell carcinoma).
    Materialart: Digitale Medien
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  • 15
    ISSN: 1432-2307
    Schlagwort(e): Human myocardium ; Left ventricle ; Electron microscopy ; Morphometry ; Aging
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Licht- und elektronenmikroskopisch wurde mit einem manuell-optischen Bildanalysesystem eine morphometrische Analyse am Herzmuskel durchgeführt. Das Untersuchungsgut stammte aus nicht belasteten menschlichen linken Ventrikeln, welches bei herzchirurgischen Eingriffen gewonnen wurde. Bei den Patienten lag entweder ein Foramen ovale persistens, ein Vorhofseptumdefekt (ASD) I.–II. Grades oder eine reine Mitralstenose III.–IV. Grades vor. Die linken Kammerdruckmittelwerte lagen im Normbereich. Das Patientengut konnte in eine junge Patientengruppe von 5–15 Jahren und in eine alte Patientengruppe von 42–78 Jahren unterteilt werden. Lichtmikroskopisch wurde ermittelt, da\ sich der Anteil des Interstitium am Herzmuskelgewebe mit dem Alter nicht verÄndert. Die Anzahldichte der Herzmuskelzellkerne nimmt im Alter ab (P〈0,001), was auf eine Verringerung der Anzahldichte der Herzmuskelzellen pro Testvolumen und eine Vergrö\erung der einzelnen Herzmuskelzelle schlie\en lÄ\t. Elektronenmikroskopisch konnte eine Vermehrung der Volumendichte der Myofibrillen (P〈0,02) mit zunehmendem Alter nachgewiesen werden, wÄhrend die Volumendichte der Mitochondrien konstant bleibt und die Volumendichte des restlichen Cytoplasmas sogar abnimmt (P〈0,05). Die Anzahl der Mitochondrien erhöht sich im Alter (P〈0,001), so da\ bei den einzelnen Mitochondrien mit zunehmendem Alter eine Verkleinerung eintritt.
    Notizen: Summary An ultrastructural and morphometric analysis was performed on human myocardial left ventricle, obtained during surgical heart operations on normally loaded ventricles. The diagnoses of the patients were a) Persistant foramen ovale b) Atrial septal defect stage (I.–II.) c) Mitral stenosis (stage III.–IV.). The median values of left ventricular pressure were not pathologically elevated. The patients were divided in 2 groups, the younger one ranging from 5–15 years, the older from 42–78 years. It was shown that the volume density of the interstitial tissue does not differ with the aging process. The number of the nuclei per test area of the heart muscle cells decreased within age (P〈0.001). This finding suggests a decreasing process in the number of the heart muscle cells and an increase in size of the individual myocardial cell. Increase in the volume density of myofibrils was demonstrated at electron microscopical level with aging (P〈0.02). The volume density of mitochondria is the same in both groups, whereas the volume density of the remaining cytoplasm (without myofibrils and mitochondria) decreases (P〈0.05). The numerical density of the mitochondria increased in the older patient group (P〈0.001).
    Materialart: Digitale Medien
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  • 16
    ISSN: 1432-2307
    Schlagwort(e): Human myocardium ; Left ventricle ; Hypertrophy ; Electron microscopy ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung An den KammerwÄnden menschlicher linker Ventrikel, die auf Grund einer Aortenstenose, einer Aorteninsuffizienz oder eines kombinierten Aortenvitium hypertrophiert waren, wurden licht- und elektronenmikroskopisch morphometrische Untersuchungen angestellt. Die Ergebnisse wurden mit denen, die an nicht belasteten menschlichen linken Ventrikeln gewonnen wurden, verglichen. Lichtmikroskopisch unterscheiden sich die Anteile der Volumendichten des Interstitium und der Herzmuskelzellen am gesamten Herzmuskelgewebe nicht statistisch signifikant. Es konnte morphometrisch eine Zellvergrö\erung festgestellt werden, die aus der signifikanten Verringerung der Volumendichte der Zellkerne (P〈0,001) und der Anzahl der Zellkerne pro TestflÄche (P〈0,0001) gegenüber den beiden Normalkollektiven resultiert. Elektronenmikroskopisch ist eine Zunahme der Volumendichten der Myofibrillen (P〈0,0001) auf Kosten des restlichen Cytoplasmas (P〈0,001) festzustellen, wÄhrend die Volumendichte der Mitochondrien im Vergleich mit den jungen und alten Patienten abnahm (P〈0,0001). Die OberflÄchendichte der Mitochondrien verringerte sich gegenüber den beiden Vergleichskollektiven (P〈0,001) ebenso wie die der Cristae mitochondriales (P〈0,0001). Diese Ergebnisse finden ihr morphologisches Korrelat in Mitochondriendestruktionen. Eine vermehrte Myolyse hat bei den hypertrophierten Herzen, die alle gewichtsmÄ\ig über dem kritischen Herzgewicht lagen, noch nicht eingesetzt. Bei allen Patienten wurde der herzchirurgische Eingriff mit Erfolg durchgeführt.
    Notizen: Summary Biopsies of hypertrophied human myocardial left ventricles were investigated morphometrically. The diagnoses of the patients were stenosis of the aortic valve, aortic insufficiency or a combination of both lesions. The results were compared with those from normally loaded human left ventricles. There are no differences on light microscopical level between the volume densities of interstitial tissue and of heart muscle cells in the three groups of patients. A significant diminution of the volume density of the nuclei (P〈0.001) and the number of nuclei per test area (P〈0.0001) when compared with normal groups suggests an increase in volume of the single heart muscle cell. The ultrastructural study shows marked increase in volume density of myofibrils (P〈0.0001), with accompanying decrease in the volume densities of mitochondria (P〈0.0001) and the remaining cytoplasm (P〈0.001). A gross decrease in the surface area of mitochondria (P〈0.001) and of cristae mitochondriales (P〈0.0001) is found. The morphological equivalents of this result are numerous stages of mitochondrial destruction including cristolysis. All myocardial weights were beyond the “critical heart weight”.
    Materialart: Digitale Medien
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Neuroradiology 15 (1978), S. 79-84 
    ISSN: 1432-1920
    Schlagwort(e): Cerebral ventriculography ; Iodophendylate and metrizamide ; Electron microscopy ; Ependyma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cerebral ventriculography was performed on adult albino rats to compare the effect of metrizamide and iodophendylate on the ependymal wall. The animals were killed by vascular perfusion 1 month and 4 months after ventriculography. The ependymal layer and the underlying brain tissue were examined with the electron microscope. After the use of metrizamide the tissue appeared completely normal. The use of iodophendylate provoked accumulation of phagocytozing macrophages on the ependymal wall and storage of iodophendylate in the ependyma and underlying brain tissue. These changes were present both 1 and 4 months after ventriculography.
    Materialart: Digitale Medien
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 25 (1978), S. 179-190 
    ISSN: 1432-0827
    Schlagwort(e): Decalcification ; Electron microscopy ; Calcified matrices
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The ultrastructure of calcifying cartilage and bone has been examined under the electron microscope after using three different methods of decalcification. The first was carried out before embedding (by soaking specimens in EDTA or formic acid), the second after embedding (by floating ultrathin sections on formic acid), and the third after embedding (by soaking embedded specimens in EDTA or formic acid), and with later re-embedding. The first procedure invariably induces drastic changes in the fine structure of the cells and calcified matrix, probably as a results of the extraction of organic material along with extraction of mineral. The second and third procedures make it possible to preserve ultrastructural details perfectly in both cells and calcified matrix. Of the two, the third procedure is preferable because of its greater simplicity. In areas that are still calcifying, these post-embedding decalcification techniques reveal the presence of crystal-associated, filamentous organic structures which are not recognizable in specimens decalcified before embedding. These structures, which could have a key role in inducing and regulating crystal formation and growth, are less evident in fully calcified areas (but not at their borders). This may partly be due to the loss of glycan components in the matrix during calcification. The most important determinant, however, seems to be the fact that during calcification the components of the matrix, including collagen fibrils, are involved in an aggregation process which reduces the amounts of free chemical groups available for reaction with the stain solution. Because post-embedding decalcification does not disturb this state of aggregation, the stainability of the matrix and the electron microscopic evidence of its components remain very low.
    Materialart: Digitale Medien
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  • 19
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 26 (1978), S. 181-190 
    ISSN: 1432-0827
    Schlagwort(e): Cellular calcium ; Electron microscopy ; Osteoblasts ; Chondrocytes ; Mineralization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The calcium distribution in cartilage and bone cells during beginning ossification of fetal mouse long bones was studied after fixation with 2% K-pyroantimonate in 1% osmium. In the developing periosteum, the future osteoblasts showed a sparse cation-antimonate precipitate over the cytoplasm. In young osteoblasts the precipitate was accumulated on the mitochondrial membranes and the plasmalemma. Both organelles were sharply outlined by precipitate in the mature osteoblasts at the onset of mineralization. X-Ray microprobe analysis of these organelles demonstrated the presence of both Sb and Ca. In the extracellular compartment, a collagen-associated precipitate with 50 to 60 nm periodicity appeared during osteoblastic differentiation. During the initial phase of matrix mineralization, a random gross precipitate appeared in the matrix and seemed to be accumulated by osmiophilic matrix vesicles while the collagen fibrils lost their precipitate. Subsequently, during the confluent phase of matrix mineralization, the precipitate rapidly disappeared from the cells, leaving them devoid of precipitate once they were surrounded by mineralized matrix. Similar changes were found in the chondrocytes of the growth plate, but cartilage collagen, unlike osteoid collagen, did not bind precipitate. The results indicate that both osteoblasts and calcifying cartilage cells bind calcium prior to matrix mineralization. Bone collagen has strong pyroantimonate binding capacity, but it is not directly involved with initial stages of matrix mineralization, which starts in close association with matrix vesicles.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Archives of toxicology 41 (1978), S. 223-232 
    ISSN: 1432-0738
    Schlagwort(e): CeCl3-hepatotoxicity ; Hypolipidemic compounds ; Peroxisomes ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Pretreatment of rats with nafenopin, a hypolipidemic compound, prevents the lethality and hepatotoxicity induced by cerium chloride (CeCl3), a rare earth metal. The increase in hepatic triglycerides and the morphologic changes observed after 48 h of the CeCl3 injection (10 mg/kg) are completely abolished by nafenopin given for 4 days in doses of 250 mg/kg. However, an increase in the frequency of peroxisomes is noted in rats receiving nafenopin and CeCl3, attributable to the hypolipidemic drug pretreatment. In comparing the protective effect of nafenopin with that of CPIB (a structurally related compound) and lentysine (a structurally unrelated agent), it can be seen that nafenopin is about five times more active in decreasing liver triglycerides. The hepatic ultrastructure of rats pretreated with CPIB or lentysine is similar to that of CeCl3-treated controls.
    Materialart: Digitale Medien
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 152 (1978), S. 235-241 
    ISSN: 1432-0568
    Schlagwort(e): Chick embryo ; Lung maturation ; Influence of pituitary ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to discover whether the embryonic chick hypophysis acts upon lung maturation directly or via its corticotrophic activity, immature lung primordia were grafted into young hosts, either alone or associated with functional adrenals or pituitaries. When lung primordia were grafted alone, type II pneumocytes did not differentiate. Their differentiation was restored when lung primordia were grafted in association with either adrenals or pituitaries. This last result, which was also obtained in vitro, shows that the hypophysis is able, by itself, to promote the maturation of respiratory epithelium.
    Materialart: Digitale Medien
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 153 (1978), S. 23-36 
    ISSN: 1432-0568
    Schlagwort(e): Electron microscopy ; Quail embryo ; Rathke's pouch
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Adenohypophyseal region of quail embryo has been examined by electron microscopy from stage 12 to stage 21 of Zacchei (1961). The Seessel's pouch develops prior to the early stages of adenohypophysis formation, then regresses while Rathke's pouch proliferates and differentiates. From Rathke's pouch formation by stage 12 (48 h of incubation) until appearance of the first secretory granules by stage 21 (6 days of incubation), there are no major ultrastructural modifications in adenohypophyseal cells. Mitochondria, Golgi vesicles, polysomic ribosomes, pinocytotic vesicles, and mitotic figures become more numerous while nucleocytoplasmic ratio and the number of ribosomes and lipid droplets decreases. The major change is the appearance of secretory granules by day 6 of incubation. This phenomenon occurs at the same time as in chick embryo, despite an incubation period shorter for quail than for chick. Mitotic figures are mainly distributed near the pouch lumen, while secretory granules are first located in the peripheral cells of the cephalic part ofpars distalis primordium. The hypothetical role of mesenchyme and vascularization is discussed.
    Materialart: Digitale Medien
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 262 (1978), S. 301-309 
    ISSN: 1432-069X
    Schlagwort(e): Lymphatic vessel(s)-lv ; Localized lymphangioma circumscriptum-Lc ; Electron microscopy ; Lymphgefäße ; lokalisiertes Lymphangiom ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Lymphgefäße (lv) in einem lokalisiertem Lymphagiom (Lc) wurde elektronenmikroskopisch untersucht. Dieses Lymphangiom, das kein Hämangiom begleitete, wies klinisch ein typisches Bild auf, und zeigte histologisch keine entzündlichen Zeichen. Die Lymphgefäße in dieser Veränderung wurden morphologisch in zwei Typen eingeteilt. Die Lymphgefäße des ersteren Typs, die im oberen Corium lagen, zeigten wie bei der experimentell induzierten Lymph-Stauung, ähnliche Bilder während diejenigen im tieferen Corium, Ähnlichkeiten zu den des normalen Lymphgefäßes erkennen lassen. Aufgrund der in dieser Untersuchung erlangten Befunde und unter Berücksichtigung der Literaturen ließ sich ableiten, daß dieses lokalisierte Lymphagiom nicht als ein echter gutartiger Tumor betrachtet wurde, sondern durch eine dauernde Lymph-Stauung in einem tumorartigen Zustand gehalten wurde.
    Notizen: Summary An electron microscopic study was performed on the lymphatic vessel (lv) of localized lymphangioma circumscriptum (Lc), which was found clinically typical but histologically not associated with hemangioma and inflammation. The lv of Lc was morphologically divided into two types. The first type was situated at the upper dermis of the lesion and the other, at the deep dermis. The former had certain similarities to lv of experimentally induced lymph-stasis, whereas the latter was morphologically similar to lv of the normal skin. From the findings of the present study and those reported in literature, Lc could not be considered as a mere benign overgrowth of lv, but as one of pathological results induced by a long-standing lymph-stasis.
    Materialart: Digitale Medien
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 262 (1978), S. 83-96 
    ISSN: 1432-069X
    Schlagwort(e): Keratohyalin ; Keratinization ; Wart ; Papilloma ; Rat tongue ; Electron microscopy ; Osmium tetroxide ; Hydrogen peroxide ; Pepsin ; Keratohyalin ; Keratinisation ; Warzen ; Papillom ; Rattenzunge ; Elektronenmikroskopie ; Osmiumtetroxid ; Hydrogenperoxid ; Pepsin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Heterogenität von Keratohyalin wurde in der Rattenzunge und in menschlichen Warzen dargestellt. Beide zeigen morphologische Ähnlichkeiten, wie dichte homogene ovoide einzelne Granula und zusammengesetzte Granula, die offenbar aus einzelnen Granula sich ableiten und von einer Membran überzogen sind. Die Ultrastruktur dieser Keratohyalinkörper wurde durch Fixierung mit Osmiumsäure nach Oxydation mit H2O2 und nach Pepsinbehandlung verglichen. Die einzelnen Granula sind osmiophil, während die zusammengesetzte Granula diese Eigenschaft nicht zeigen. Bei menschlichen Warzen zeigte sich eine fehlende Oxydierung durch H2O2 der einzelnen Granula, während die zusammengesetzten Granula oxydationsempfindlich sind. In der Zunge von neugeborenen Ratten zeigten sich die umgekehrten Verhältnisse. Diese Unterschiede zeigen, daß es unmöglich ist, die Bildung von Keratohyalingranula auf dem gleichen Wege zu erklären, wie die der Keratohyalingranula bei den Ratten, obwohl ultrastrukturelle Ähnlichkeiten bestehen. Es erscheint wichtig darauf hinzuweisen, daß die Keratogenese und die Keratohyalingranulabildung, die bei den Verrucae vulgaris vorliegt, von der Keratohyalinentwicklung in der Rattenzunge sich unterscheidet.
    Notizen: Summary The heterogenecity of keratohyalin (KH) has been demonstrated in rats, then in human warts where similar morphological features have been found and among them, dense homogeneous ovoïd single granules (SG) and composite granules (CG) apparently made up of single granules “coated” with a matrix. This work compares the ultrastructure of the KH of the tongue of newborn rats with that of common warts with and without post-fixation by OsO4, after oxydation by H2O2 and after pepsin treatment. The osmiophily of the SG is confirmed as well as the absence of osmiophily of the matrix of the CG. In man, however, the SG are resistant to oxydation by H2O2 and the CG matrix is oxydation sensitive whereas the opposite is observed in the case of rats. These differences show that it is impossible to deduce the composition of the KH in human warts from that of the rat despite their close ultrastructural resemblance but that important modification of the keratogenesis and KH formation are induced in the cells parasited by the virus of common warts.
    Materialart: Digitale Medien
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  • 25
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 263 (1978), S. 227-233 
    ISSN: 1432-069X
    Schlagwort(e): Erythrocytes ; Painful bruising syndrome ; Freeze-etching ; Electron microscopy ; Rote Blutzellen ; ≫Painful bruising≪-Syndrom ; Gefrierätzung ; Elektronen-Mikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei 3 Patienten mit dem Gardner-Diamond Syndrom oder dem ≫painful bruising≪-Syndrom sind morphologische Abweichungen an roten Blutzellen festgestellt worden. Von diesen roten Zellen, die bei der Ficoll/Isopaque Gradient Zentrifugation nicht sedimentierten, werden teilweise keulenförmige Ausläufer, Mitochondrien, Kernreste und Vacuolen festgestellt. Bei pH 7.4 zeigten 90% der roten Blutzellen in Gefrierätzparaten Ausbuchtungen auf der Membran, während bei pH 6,4 noch 25% der roten Zellen diese Erhebungen zeigten. Im Kontrolpräparaten waren diesen Zahlen 55% und 0% unterschiedlich bei pH 7.4 und 6.4. Die Geldrollenbildung im Blut von Patienten mit dem ≫painful bruising≪-Syndrom war stark erhöht.
    Notizen: Summary Red cells of 3 patients with the painful bruising syndrome showed morphological anormalities. In the fraction not sedimenting in Ficoll/Isopaque gradient centrifugation, some of these cells had club-shaped processes, mitochondria, nuclear remnants, and vacuoles. In freeze-etch preparations, 90% of the red cells showed membrane elevations at pH 7.4 and 25% at pH 6.4, while in freeze-etch preparations of controls these values were 55 and 0 respectively. In addition, rouleaux formation was markedly enhanced in the preparations of blood of patients with the painful bruising syndrome.
    Materialart: Digitale Medien
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 153 (1978), S. 287-293 
    ISSN: 1432-0568
    Schlagwort(e): Mouse embryos ; Visceral yolk sac ; Trypan blue ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural features of the early visceral yolk sac epithelium of normal mouse embryos on day 9 were compared to those whose mothers had received a single subcutaneous injection of 100 mg/kg trypan blue on day 8. The following results were obtained: In normal embryos the visceral yolk sac cells are predominantly characterized by numerous membrane bounded inclusions localized in the supranuclear cytoplasm. In embryos of animals treated with trypan blue, at about 12h after injection large single and only partly membrane bounded vacuoles are observed occupying most of the apical cytoplasm. Up to 24h after injection large cytoplasmic areas are seen which are in a stage of autodigestion possibly due to leakage of the vacuolar content. These alterations are exclusively limited to the visceral yolk sac epithelium whereas in the cells of the embryonic part, e.g. head process, no changes could be found. The observations are discussed in relation to the mechanism of the teratogenic activity of trypan blue.
    Materialart: Digitale Medien
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  • 27
    ISSN: 1432-0568
    Schlagwort(e): Myofibrillogenesis ; Human heart ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The myofibrillogenesis in the human embryonic heart is described. The synthesis of thin filaments, which are the first to appear, takes place in close proximity to smooth surfaced SR tubules. Z-band material is closely related to the thin filaments and appears first as irregularly distributed patches in the filamenteous mass. Further cellular differentiation includes an organization of the thin filaments/Z-band material. The synthesis of thick filaments, which follows that of the thin filaments, takes place in ribosome rich areas of the cell. They are rapidly incorporated into the strings of organized thin filaments/Z-band material. The periodic binding sites on both kinds of filaments are believed to play an important role in the precise ordering of the filaments. The formation of myofilaments in the adult hypertrophied human heart is also described. The similarities between this process and that observed in the embryonic heart are striking, and we believe it to be the same process.
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Anatomy and embryology 152 (1978), S. 223-234 
    ISSN: 1432-0568
    Schlagwort(e): Chick embryo ; Lung maturation ; “in ovo” decapitation ; Lung lipids ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effects of “in ovo” hypophysectomy on lung maturation of the chick embryo were investigated. Both biochemical and morphological aspects of differentiation were markedly delayed in experimental embryos: the phospholipid content of lungs was lower than in controls at all stages, whereas the water content remained very high. The type II pneumocytes, which normally appear within the epithelium on day 16 of incubation, started to differentiate only between days 18 and 20 of incubation in the decapitated embryos. The differentiation of type I pneumocytes leading to the formation of air capillaries was also slowed down: they did not appear until the end of incubation in decapitated embryos, whereas they normally start to appear on day 19. The presence of an intact hypophysis is thus essential for normal lung maturation in the chicken.
    Materialart: Digitale Medien
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  • 29
    ISSN: 1432-0533
    Schlagwort(e): Toxoplasma gondii ; Encephalitis ; Central nervous system ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The fine structure and reproductive mechanisms of Toxoplasma gondii are described in a case of toxoplasma encephalitis. Replication was observed in glial cells by an internal budding process: endodyogeny. Distinctive ultrastructural features associated with host cell penetration, and encystation are described. Electron microscopic features previously reported in tissue culture and in experimentally produced infections with T. gondii are confirmed in the human brain tissue.
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 121-126 
    ISSN: 1432-0533
    Schlagwort(e): Nerve fiber teasing ; Phase contrast microscopy ; Electron microscopy ; Axonal and myelinic disorder ; Wallerian degeneration ; Secondary segmental demyelination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The changes in a sural nerve biopsy of a patient with porphyric neuropathy were studied by light and electron microscopy. Linear arrays of myelin ovoids constituted the most common abnormality in whole mounts of teased-fiber preparations. Round or irregular formations of variable osmiophilia were the most frequent finding in thick-section preparations examined by phase contrast microscopy. Lamellar whorls represented the most prevalent lesion in thinsections studied under the electron microscope. In addition, along the teased fibers, segmental demyelination was definitely detected, although rarely; in thick sections, the true extent of the nerve fiber loss was fully appreciated; in thin sections, a variety of axon and myelin changes of a distinct character were discovered. The studies demonstrate that in peripheral nerves of porphyric neuropathy, axonand myelin changes generally run together and proceed pari passu in the same segment of nerve fiber. Furthermore, among the pathogenetic mechanisms invoked to account for the neuropathic changes none are favored to the exclusion of others by these studies. Therefore, a primary axonaland myelinic disorder on the basis of a deranged porphyrin metabolism is as good a possibility as any hitherto advanced explanation of the pathogenesis of the neuropathic changes. The secondary lesions of Wallerian degeneration and segmental demylination may simple be grafted upon the primary lesions evoked by the metabolic abnormality.
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 211-215 
    ISSN: 1432-0533
    Schlagwort(e): Canine CNS ; Myelination ; Hypomyelinogenesis ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Five Chow-Chow dogs from three different litters had generalized body tremors since birth. Histologically a severe myelin deficiency was found in the central nervous system. The peripheral nerves were normally myelinated. Electron microscopically abnormally thin myelin sheaths and completely naked nerve fibers were found. There were many astrocytes in the myelin deficient areas as well as cells with the characteristic features of oligodendrocytes but also containing fibrils. The present cases are compared to other dysmyelinating diseases and possible pathogenetic mechanisms are discussed.
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  • 32
    ISSN: 1432-041X
    Schlagwort(e): Synaptogenesis ; Electron microscopy ; Visual acuity ; Fish development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The morphogenetic differentiation of synapses of the optic tectum of the rainbow trout was investigated at different stages of development (from hatching to adult) and compared with the improvement in visual discrimination (minimum separable). (1) The main phase of synaptogenesis (increase in number of synapses, length of contact zone and number of vesicles) begins about one week after hatching and continues up to the age of one month, when the larvae start swimming freely. (2) Myelination begins 26 days after hatching and induces the end of the synaptogenesis period. (3) The visual discrimination (minimum separable) of trout larvae improves from 30 degrees of arc on the 10th day after hatching to 1 degree on day 30, then to about 14 to 18 min of arc in the adult. The results are discussed with special reference to previous biochemical investigations on changes in the ganglioside composition of the trout brain during comparable periods of development.
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 25 (1978), S. 133-143 
    ISSN: 1432-0827
    Schlagwort(e): Osteon ; X-Ray diffraction ; Electron microscopy ; Calcification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary To obtain information on the changes in the inorganic bone fraction during calcification, low- and wide-angle X-ray diffraction techniques and electron microscopy have been applied to single osteon samples. The samples were cylindrically shaped and their axes corresponded to the axes of the Haversian canals. The selection was made according to the degree of calcification and the orientation of collagen bundles and inorganic particles. Osteons at both the initial and final stages of calcification were chosen. Arrangements of fiber bundles and inorganic particles in successive lamellae characteristic of three types of osteon were selected, that is, longitudinally structured osteons, transversely structured osteons, and alternately structured osteons. The results indicate that in osteonic lamellar bone there are two types of inorganic particles: (1) granules arranged in linear or needle-shaped entities with maximum width 40–45 Å, which are regularly distributed at the level of the main band of the collagen fibrils where their maximum length reaches the length of the main band itself; that is, about 400 Å; and (2) very long crystallites, with a diameter of 40–45 Å, which grow with their crystallographicc-axis parallel to the collagen fibrils and cover much more than a major collagen period.
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 25 (1978), S. 217-222 
    ISSN: 1432-0827
    Schlagwort(e): Bone mineral ; Electron microscopy ; X-ray diffraction ; Dark field
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Electron microscopical observations of the size and shape of bone mineral crystallites have not been in complete agreement with X-ray diffraction findings. The two prevalent viewpoints consider bone mineral crystals to be either rod, or plate like in habit. There appears to be agreement that the smallest dimension of the crystals is about 5 nm, but there is discrepancy in the reported c-axial lengths. The method of dark field imaging is used to obtain a quantitative measurement of the c-axial length distribution in rabbit, ox and human bone: mean c-axial lengths 32.6 nm, 36.2 nm and 32.4 nm, respectively, show no significant difference at the 5% level to the mean c-axial length measured by X-ray line broadening. Both bright and dark field images strongly suggest that bone mineral has a plate like form. Reasons for past discrepancies are discussed.
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 25 (1978), S. 45-51 
    ISSN: 1432-0827
    Schlagwort(e): CaCO3 ; Amino acids ; Sheaths ; Ligament ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The aragonite crystals in the molluscan bivalve hinge ligament are surrounded by an organic sheath which is distinct from the remainder of the ligament matrix. Methods have been developed to isolate these sheathed crystals from the ligaments ofSpisula solidissima andMercenaria mercenaria employing a papain digestion of the matrix protein. The sheathed crystals fromSpisula have a CaCO3/protein ratio of 11.1 and those fromMercenaria a ratio of 29.6. The sheathed crystals and the empty crystal sheaths have been examined by electron microscopy for structural integrity. The sheath proteins exhibit much smaller proportions of the amino acids glycine and methionine than the hinge ligaments. These are characteristic amino acids of high concentration in the hinge ligaments of both species. The concentrations of acidic and basic amino acids are increased about two fold in the sheaths over those of the ligaments. Otherwise there is little similarity in the amino acid composition of the sheaths in the two species. However, SDS electrophoresis shows the sheaths of both to contain a major protein component with a molecular weight of about 25,000. The sheath protein from theMercenaria ligament contains about 5% carbohydrate and that ofSpisula sheaths less than 1% carbohydrate.
    Materialart: Digitale Medien
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    European journal of pediatrics 127 (1978), S. 75-89 
    ISSN: 1432-1076
    Schlagwort(e): Hyperinsulinism ; β-cell hyperplasia ; Nesidioblastosis ; Newborn ; Infants ; Somatostatin ; Electron microscopy ; Therapy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Two patients with severe hypoglycemia since birth are described. In both hyperinsulinism was demonstrated during spontaneous hypoglycemic attacks or could be provoked by various tolerance tests. In case I considerable obesity and psychomotor retardation was present at the age of one year whereas in case II weight gain was normal and development unaffected. Immunofluorescence microscopic and electron microscopic examination of the pancreas after subtotal pancreatectomy revealed diffuse islet cell hyperplasia with nesidioblastosis in case I and β-cell nesidioblastosis in case II. The hyperplastic and nesidioblastotic areas consisted mainly of β-cells. In addition, an accumulation of somatostatin producing cells was observed in case I, and some cells were found with ultrastructural signs of both endocrine and exocrine function. In both cases, pancreatic insulin release was inhibited by a prolonged somatostatin infusion. The results of tolerance tests did not allow a diagnosis of the underlying pancreatic lesion. In case II, leucine-sensitive hypoglycemia detected soon after birth, was present even after subtotal pancreatic resection. Therapeutic trials with diazoxide in case I and a leucine-restricted diet in case II were only of temporary benefit. After subtotal pancreatectomy there was clinical improvement in both cases, but case II still needs a leucine-restricted diet. The familial occurrence of persistent hypoglycemia in both cases suggests that β-cell nesidioblastosis may be a hereditary disorder.
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 261 (1978), S. 7-16 
    ISSN: 1432-069X
    Schlagwort(e): Erythema elevatum diutinum ; Extracellular cholesterosis ; Electron microscopy ; Lipid deposition ; Vasculitis ; Erythema elevatum diutinum ; Extracelluläre Cholesterinose ; Elektronenmikroskopie ; Lipidablagerung ; Vaskulitis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung 1. Ein typischer Fall von Erythema elevatum diutinum (E.e.d.) mit extracellulärer Cholesterinose bei einer 48jährigen Patientin mit bisher 15 Jahre dauerndem Verlauf wird klinisch und histologisch beschrieben. 2. Elektronenmikroskopisch wird die histologisch und immunfluorescenzmikroskopisch nachgewiesene leukocytoklastische Vaskulitis bestätigt. In älteren Herden herrschen Histiocyten/Makrophagen vor. Intra- und extracelluläre Lipidablagerungen erscheinen elektronenmikroskopisch unter verschiedenartigen Bildern, die sich in ihrer Gesamtheit von allen anderen bisher ultrastrukturell beschriebenen Krankheiten mit Lipidablagerungen unterscheiden. 3. Die Befunde sind mit der Hypothese vereinbar, daß primär bei E.e.d. eine besondere Form von chronischer leukocytoklastischer Vaskulitis vorliegt und die Lipidablagerungen sekundär auf dem Boden von Gefäßwandschädigungen und Nekrosen entstehen.
    Notizen: Summary 1. A typical case of Erythema elevatum diutinum (E.e.d.) with extracellular cholesterosis is described clinically and histologically in a 48-year-old woman. The disease had a course of 15 years. 2. Electron microscopy confirmed the histological and immunfluorescent findings of leucocytoclastic vasculitis. In older lesions, histiocytes/macrophages predominate. Intra- and extracellular lipid depositions showed a variety of ultrastuctural characteristics which differed from electron microscopical findings described in other disorders associated with lipid deposition. 3. The findings are in accordance with the hypothesis that the primary event in E.e.d. is a special type of chronic leukocytoclastic vasculitis. Subsequently, the damage of the vessel walls and focal necrosis may lead to secondary lipid deposition.
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 119 (1978), S. 303-304 
    ISSN: 1432-072X
    Schlagwort(e): Vibrio cholera phage group II ; Properties ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The basic physical, chemical and physiological properties of a group II cholera phage belonging to Mukerjee's classification has been described.
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 119 (1978), S. 227-229 
    ISSN: 1432-072X
    Schlagwort(e): Cell wall ; Electron microscopy ; Methylomonas albus ; Goblet sub-units
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In surface view, the cell wall complex ofMethylomonas albus possesses a hexagonal pattern of ridges. Thin sections reveal a continuous layer of goblet-shaped elements attached to the outermost surface of the lipopolysaccharide membrane. A possible interpretation of the cell wall complex ofM. albus, based on the fine-structural data is presented.
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 116 (1978), S. 133-139 
    ISSN: 1432-072X
    Schlagwort(e): Lagenisma ; Coscinodiscus ; Infection ; Endosymbiotic bacteria ; Tip growth ; Wall-less thallus ; Host-parasite interface ; Membranes ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Lagenisma coscinodisci is diplanetic and has two different cyst stages. The secondary cyst has a uniform cell wall of fibrillar material. It attaches to a Coscinodiscus frustule and germinates with an infection tube. The cyst becomes filled with an enlarging expulsion vacuole. The infection tube penetrates the diatom cell between the cingula. Inside the host cell the fungus grows as an irregularly branched wall-less thallus. In the hyphae apical vesicles are lacking. The infection tube is plugged by wall material. There are no microtubules which might participate in the morphogenesis of the thallus. The plasmalemma of the diatom is pushed inward but not pierced by the fungus. Along the host-parasite interface it lies closely paralled to the Lagenisma plasmalemma which is extremely straight here and measures about 10 nm instead of about 5–6 nm at the surfaces of other stages. The Coscinodiscus plasmalemma disintegrates at about the same time when the cytoplasm breaks down. The fungus allows bacteria to enter the diatom; there are also endosymbiontic bacteria in unattacked cells — The growth mechanisms are discussed and the host-parasite interface is compared with that of other fungi.
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 118 (1978), S. 67-69 
    ISSN: 1432-072X
    Schlagwort(e): Corynebacterium autotrophicum ; Outer Membrane ; Lipopolysaccharides ; Biochemical analysis ; Polymyxin B ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Lipopolysaccharides (LPS) from Corynebacterium autotrophicum were isolated and analyzed. Autotrophically grown cells contained 2–5 mg of partly purified LPS per g dry weight of lyophilized cells. Serological cross reaction with Lipid A antigen of Salmonella minnesota confirmed the presence of LPS in C. autotrophicum. Electron microscopy of negatively stained Polymyxin B-treated cells showed formation of blebs on the Outer Membrane indicating an interaction of Polymyxin B specifically with LPS. Up to now, no Gram-positive organisms are known which contain any LPS. Thus, C. autotrophicum, though giving opposite results when the Gram-staining reaction was applied by several authors, has to be classified into the group of Gram-negative bacteria.
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 118 (1978), S. 305-308 
    ISSN: 1432-072X
    Schlagwort(e): Carotenoid mutant strain R-26-Rhodopseudomonas sphaeroides ; Electron microscopy ; Intracellular membranes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Stained thin-sections and freeze-fractured preparations of the carotenoid-less mutant strain R-26 of Rhodopseudomonas sphaeroides grown photosynthetically revealed 2 morphological kinds of intracellular membrane systems- spherical vesicles distributed throughout the cytoplasm and lamellae confined to the periphery of the cell. The lamellar membranes appeared to be large, flattened vesicles.
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 119 (1978), S. 87-90 
    ISSN: 1432-072X
    Schlagwort(e): Salmonella typhimurium strain LT2 (ColIb) ; Cryptic plasmids ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Small cryptic plasmids of molecular weights ranging from 1 to 3 Mdal were detected by electron microscopy in Salmonella typhimurium strain LT2 (ColIb). They were divided into different size classes. Two of the cryptic plasmids were transferred simultaneously with ColIb to Escherichia coli.
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 263 (1978), S. 47-58 
    ISSN: 1432-069X
    Schlagwort(e): Candida albicans ; 8-Methoxypsoralen ; UVA ; Electron microscopy ; Candida albicans ; 8-Methoxypsoralen ; UVA ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Candida (C.) albicans Zellen wurden 8-Methoxypsoralen (8-MOP) Konzentrationen von 1,0 μg/ml und 10,0 μg/ml Medium ausgesetzt und anschließend mit UVA (365 nm) bestrahlt. Die Bestrahlungsdosis betrug 4,8 J/cm2. Zwei unterschiedliche Arten von Zellschäden wurden beobachtet, die einmal das Cytoplasma und dessen Organellen, zum andern die Zellwand der Hefezellen betrafen. 2h nach Abschluß der Bestrahlung sah man Unregelmäßigkeiten der Form der Mitochondrien, die mitochondrialen Membranen waren verschwommen, die Cristae schwer oder nicht erkennbar. Die Zahl der Vacuolen war erhöht. Das Cytoplasma war von unregelmäßig begrenzten Bezirken verminderter Elektronendichte durchsetzt, die cytoplasmatische Membran war stellenweise nicht darstellbar. Kern und Kernhüllen ließen zu diesem Zeitpunkt keine Auffälligkeiten erkennen. 24 h nach Behandlungsende traten zusätzlich eigentümliche Veränderungen der Zellwand auf. Neugebildete Zellwandmassen saßen der innersten Wandschicht kugel-oder sichelförmig auf. Die Untersuchungen legen nahe, daß die nach kombinierter Anwendung von 8-MOP und UVA an C. albicans Zellen erhobenen Befunde nicht im Sinne einer allgemein cytotoxischen Wirkung interpretierbar sind. Anscheinend handelt es sich um ein Kombinationsgeschehen aus regressiven und progressiven Veränderungen.
    Notizen: Summary Candida (C.) albicans cells were exposed to 8-Methoxypsoralen (8-MOP) concentrations of 1.0 μg/ml and 10.0 μg/ml medium and irradiated with 365 nm light. The amount of energy emitted was 4.8 J/cm2. Two divergent types of cell damage occured concerning yeast cell cytoplasm and cell wall. Two hours after exposure cytoplasmic changes involving mitochondria, which showed irregularities in shape, blurred appearance or loss of mitochondrial cristae and outer membrane were seen. The number of vacuoles was increased. The cytoplasm showed large electron transparent areas, the cytoplasmic membrane disappeared in some areas completely. Nucleus and nuclear envelope usually remained intact in early stages. 24h after exposure conspicuous cell wall alterations were observed in addition to cytoplasmic changes. Newly produced cell wall material formed ball-like protrusions or was adherent sickle-shaped to the cell wall. The investigations strongly suggest that the results found after 8-MOP-UVA treatment of C. albicans cells can not be interpreted in the sense of a general cytotoxic effect. Apparently it takes the form of a combination of events involving regressive and progressive alterations.
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  • 45
    Digitale Medien
    Digitale Medien
    Springer
    Archives of dermatological research 263 (1978), S. 1-12 
    ISSN: 1432-069X
    Schlagwort(e): Viral papilloma ; Flat warts ; Epidermodysplasia verruciformis ; Human papovavirus ; Electron microscopy ; Virusales Papillengeschwulst ; Warzen ; Epidermodysplasia verruciformis ; Papovavirus beim Menschen ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei der Beantwortung der Fragen, ob die Epidermodysplasia verruciformis (E. V.) und die disseminierten Warzen verschiedene Erkrankungen sind, wurde eine vergleichende ultrastrukturelle Studie der epidermalen Klarzellen von zwei Fällen von E.V. und 4 Warzen von 4 Patienten, bei denen 3 unter immunsuppressiver Therapie standen, vorgenommen. Bei der E.V. wurde eine Reduktion der Tonofilamente und des Keratohyalins und bei den flachen Warzen ein zentrifugales Ödem und eine Vakuolisierung festgestellt. Die Zahl der Ribosomen war beim E.V. erhöht und vermindert bei den flachen Warzen. Somit können diese beiden Erkrankungen untereinander differenziert werden und weisen auf eine unterschiedliche Gast-Virus-Beziehung hin.
    Notizen: Summary Are Epidermodysplasia verruciformis (E. V.) and disseminated flat warts different diseases? Are there any diagnostic criteria between them? In order to attempt answering these 2 questions, fundamental for prognosis and nosology, a comparative ultrastructural study was made of epidermal clear cells of 2 cases of E. V. and 4 flat warts from 4 patients of whom 3 were under immunosuppression drugs. The reason of cytoplasmic electron translucency was mainly a reduction in tonofilaments and keratohyalin amounts in E. V. and a centrifugal edema and vacuolization in flat warts. On the other hand, the number of ribosomes was raised in E. V. and reduced in flat warts. These findings allow differentiation between the 2 diseases and suggest a possible different host-virus relationship.
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 41 (1978), S. 91-95 
    ISSN: 1432-0533
    Schlagwort(e): GM1 gangliosidosis ; Friesian calves ; Clinical retinoscopy ; Ocular pathology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Late-onset of disturbed vision is a clinical feature of bovine GM1 gangliosidosis. Studies on eight affected calves showed that ocular lesions were confined to the retinae and optic nerves. Myriad tiny white spots were visible by ophthalmic examination of the fundus. These spots were related to protuberances on the vitreal surface caused by distended retinal ganglion cells. The perikaryons of these cells were packed with dense aggregates of membranous cytoplasmic bodies (MCBs). Similar MCBs were present in the perikaryons of amacrine cells in the inner nuclear layer of the retina. Wallerian degeneration was present in the optic nerves. The lesions were compared with those described in gangliosidosis in man, cats, pigs and dogs. It is suggested that examination of the fundus is a useful clinical procedure in the diagnosis of bovine GM1 gangliosidosis.
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 41 (1978), S. 207-210 
    ISSN: 1432-0533
    Schlagwort(e): Brain ; Hypercapnia ; Electron microscopy ; Histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Thirteen adult rabbits were exposed to a breathing air mixture containing an increasing amount of CO2 for eight weeks. When the CO2 content reached 9 Vol% the animals became apathic and lost body weight. The EEG showed a reduction of the amplitudes of 10 Hz frequences. Blood gases revealed an increase of bicarbonate but no change of pH. The blood brain barrier which was tested when the animals were killed was not disturbed. Enzyme histochemistry, light and electron microscopy revealed that moderate brain edema had occurred. From these results it is concluded that chronic hypercapnia has a hypnotic effect which in combination with chronic edema may depress vital activities considerably. However, there seem to be no irreversible morphological alterations of the brain.
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  • 48
    ISSN: 1432-0533
    Schlagwort(e): Cultured ; Craniopharyngioma ; Typical ; Atypical ; Ultrastructure ; Electron microscopy ; Biochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Craniopharyngiomas are tumors of the suprasellar area, which are often cystic, encapsulated and slow-growing. Certain of these tumors can behave in an aggressive manner and either invade surrounding structures or recur. In order to determine characteristics which may aid in distinguishing typical from atypical lesions, a study of biopsy and tissue culture specimens from 25 human craniopharyngiomas was undertaken. Tissue culture observations reveal two distinct cell populations. Typical lesions grew in culture in an orderly epithelial pattern and had desmosome-tonofibril aggregates and smooth surface topography demonstrable by electron microscopy. In the atypical tumors the cell growth was irregular, with mitotic activity, cholesterol crystals and features characteristic of neoplastic transformation, such as surface microvilli, an increase of cytoplasmic basophilia, size and number of nucleoli and retraction of cytoplasm. Correlation with the clinical status of the patients suggests that tumors of the four patients which exhibited atypical features in culture behaved more aggressively.
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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 217-222 
    ISSN: 1432-0533
    Schlagwort(e): Lafora-like inclusion bodies ; Aging ; Dog ; High incidence ; Comparative neuropathology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Forty randomly selected dogs, arranged into three groups according to age, were examined light and electron microscopically. Lafora-like inclusion bodies were found in all cases of aged dogs without neurological signs. They appeared as PAS positive, round bodies measuring up to 15μm in diameter. Typically they had central cores and radiating peripheral lines. Electronmicroscopically, the inclusions consisted of irregularly clustered, short branching filaments measuring about 80–120 Å in diameter or of electrondense homogeneous or granular central cores with filamentous peripheral areas and located both in the perikarya and neuronal processes. The inclusions were disseminated all over the brain and spinal cord. The thalamic nuclei, a circumscribed area dorsal to the aqueduct, and the molecular layer of the superior colliculus were the most severely affected. The frequency of the inclusions showed age-dependency; the inclusions were not found in dogs younger than 2 years, but were extensive in all dogs of more than 8 years of age. The occurrence of the inclusions may therefore represent an age-dependent phenomenon. The relationship between the present findings and Lafora's disease is discussed.
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 63-70 
    ISSN: 1432-0533
    Schlagwort(e): Corona virus ; Weanling rats ; Demyelination ; Immunofluorescence ; Electron microscopy ; Oligodendrocyte and Astrocyte
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Thirty percent of weanling rats infected with JHM murine corona virus developed a subacute demyelinating encephalomyelitis approximately 3 weeks after intracerebral inoculation. Small demyelinating foci were located in the deep cerebral white matter and large, sharply demarcated demyelinating lesions were detectable in optic chiasma, pons and spinal cord. Axons as well as neurons were well preserved in the demyelinating plaques in areas where the lesions extended to the gray matter. Perivascular cuffings, consisting of plasma cells and mononuclear cells, were frequently found. Viral antigen was found mostly in the white matter and in glial cells, leaving neurons unstained. Electron microscopic studies of the early lesions of white matter disclosed two different kinds of cell degeneration which developed prior to the myelin disruption and mononuclear cell infiltration. One was a small pyknotic cell, which is thought to be an oligodendrocyte and the other is a ballooned cell containing abundant microtubules. Virus particles could be demonstrated only in the latter cell type. Discussion about astrocytes as well as oligodendrocytes was made in relation to the initial stage of demyelination caused by virus infection. This animal model may be useful in the analysis of the mechanisms leading to demyelination in subacute or chronic infections.
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  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Annals of hematology 36 (1978), S. 149-157 
    ISSN: 1432-0584
    Schlagwort(e): Plasmazellen ; Nichtsekretorisches Myelom ; Elektronenmikroskopie ; Plasma cells ; Non-secretory myeloma ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary A case of “non-secretory” multiple myeloma is described. The diagnosis was based on the clinical picture, typical radiological findings, and infiltration of the bone marrow by myeloma cells which showed specific immuno-fluorescence staining mainly with antisera for IgM and kappa light chains. An attempt is made to explain the absence of pathological proteins in the serum, based on the ultrastructural findings of the myeloma cells, which showed “buddings” of the cell membranes containing endoplasmic reticulum and cytoplasmic material. It is suggested that the cells of the “non-secretory” type of multiple myeloma possess a normal excretory mechanism, but the pathological proteins are prevented to be secreted in the serum being surrounded by portions of the cell membrane.
    Notizen: Zusammenfassung Bei einem Patienten mit nichtsekretorischem Plasmozytom wurden die Plasmazellen immunologisch und elektronenmikroskopisch untersucht. Die Diagnose beruhte auf dem klinischen Bild, den typischen Röntgenbefunden und einer Infiltration des Knochenmarks durch Plasmozytomzellen, die eine spezifische Immunfiuoreszenz mit Antiseren für IgM und kappa-Leichtketten zeigten. Es wird versucht, das Fehlen des Paraproteins im Serum mit Hilfe der elektronenmikroskopischen VerÄnderungen zu erklÄren. In den Plasmazellen der nichtsekretorischen Myelome wird die Sekretion der Paraproteine wahrscheinlich dadurch verhindert, da\ sie durch Membranfragmente eingeschlossen werden.
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  • 52
    ISSN: 1432-0533
    Schlagwort(e): Alcohol ; Polyneuropathy ; Rat peripheral nerve ; Electron microscopy ; Cholinesterases ; Electrophysiology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Peripheral nerves and myoneural junctions of the tibialis anterior muscle of the rat were studied histologically and electrophysiologically after various periods of peroral ethanol treatment. Histochemical distributions of non-specific cholinesterase (ns. ChE; E.C. 3.1.1.8) and acetylcholinesterase (AChE; E.C. 3.1.1.7) activity of the muscle were normal during the first 3 months of daily ethanol drinking. After 5 months of exposure to 10–25% (v/v) ethanol as the sole drinking fluid, pathological ns. ChE activity was seen sporadically along the intramuscular nerves with slight ultrastructural changes in the Schwann cells. After 7 months of ethanol treatment there was further increased pathological ns. ChE activity in the intramuscular nerves while the AChE activity remained normal in the muscle. More prominent ultrastructural changes were seen in the Schwann cells namely swelling and vacuolization of the cytoplasm and dilatation of the rough endoplasmic reticulum. Increased numbers of small axons were also seen. After 9.5 months on alcohol marked increase in the ns. ChE activity was observed along most of the intramuscular nerves. AChE activity of the myoneural junctions was only sporadically weakened. A slight slow-down in the conduction velocity of the large myelinated size A fibers was observed in the animals on alcohol from 7–9.5 months, whereas the conduction velocity of the smaller myelinated B fibers was not appreciably changed. The present experiment indicates that progressive neuropathy can be induced in rats by oral alcohol feeding along with the normal laboratory diet. The first pathological changes were seen in the Schwann cells and could well be followed by the methods employed. The present experimental model can possibly be used in future studies concerning the development of toxic polyneuropathy.
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  • 53
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 59-62 
    ISSN: 1432-0533
    Schlagwort(e): Meningioma ; Hyaline inclusions ; Colloid bodies ; Pseudopsammomas ; Lamellar structures ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary One case of meningiothelial meningioma with “hyaline inclusions” (colloid-bodies or pseudopsammomas) as noted by Cushing and Eisenhardt (1938) and by Kepes (1961–1975) is reported by light and electron microscopy. Two types of these structures, either homogeneous or polymorphic, surrounded by microvilli are described and regarded as signs of secretory differentiation of tumor cells. In addition to Kepes' description, the authors show, at high magnification, the polymorphic material including homogeneous component, lamellar structures, microvesicles and dense bodies. The endocellular overproduction of the various types of “hyaline inclusions” and the nature of their material are discussed.
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  • 54
    ISSN: 1432-0533
    Schlagwort(e): Muscle ; Myotonia ; Hypocholesterolemic drugs ; Desmosterol ; Electromyography ; Zuclomiphene ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The present study presents evidence for a third hypocholesterolemic drug, zuclomiphene, being able to induce an experimental myotonic condition. Other drugs used singly or in combination were AY-9944. Triparanol and 20, 25-diazacholesterol. It has also been demonstrated for the first time that experimental myotonia can be induced in developing rats as well as adults. Developing rats received the initial intraperitoneal injection of drug at 5 days of age and were examined at 50 days of age. Adult rats were treated for 5 weeks. Two injections were given per week. Positive electromyography findings were observed in the developing and adult animals receiving 20, 25-diazacholesterol and zuclomiphene. The electromyography data of the other regimens of treatment were equivocal with regard to myotonia. Histological, histochemical, and electron microscopic examination of the muscle demonstrated no important changes. Estimation of sterol composition showed that desmosterol was a major sterol in muscle after 20, 25-diazacholesterol or zuclomiphene treatment, thus furthering the concept that it is desmosterol in the muscle membrane, and not the drug, that is responsible for the myotonic condition.
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  • 55
    ISSN: 1432-0533
    Schlagwort(e): Arachnoid cysts ; Subdural neurothelium ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Three surgically removed primary arachnoidal cysts were studied with scanning electron microscopy (SEM) and two of the cases with transmission electron microscopy (TEM). The cells lining the cyst cavity had microvilli at the surface, true cilia were absent. In the cytoplasm multivesicular bodies, many pinocytotic vesicles, some large vacuoles and strands of tonofilaments were prominent features. The cells were interconnected by desmosome-like junctions and were interconnected by desmosome-like junctions and were separated from the surrounding tissue by a distinct but sometimes incomplete basal membrane. Based on these findings it is concluded that arachnoid cysts are derived from the outer arachnoid cells (subdural neurothelium), the formation of the cysts being attributable to secretory capacity of the subdural neurothelium.
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  • 56
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 217-221 
    ISSN: 1432-0533
    Schlagwort(e): Toxoplasma ; Cerebral toxoplasmosis ; Immunosuppression ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The morphology of toxoplasma and its interaction with the cellular elements of the brain were studied in a patient who died of extensive cerebral toxoplasmosis superimposed on Hodgkin's disease. The cerebral lesions were devoid of inflammatory cellular response and contained numerous organisms mostly in isolated multiplying forms in neurons, glia and vascular walls. Encysted forms containing multiplying organisms were seen infrequently. Intracellular parasite was identified in normal-appearing neuropil. The mode of multiplication and cyst formation of toxoplasma appeared basically similar to that described under experimental conditions. In addition, a rapid evolution of the cerebral lesions was suggested by computerized tomography. This study suggests that tissue necrosis in human cerebral toxoplasmosis is the result of an increased rate of multiplication and enhanced cellular invasiveness of the parasite most likely related to impaired cellular immunity as has been postulated by clinical and experimental data.
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  • 57
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 41 (1978), S. 229-234 
    ISSN: 1432-0533
    Schlagwort(e): Atypical senile dementia ; Electron microscopy ; Two types of filaments (neurofibrillary tangles)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A man aged 70, showed early disorientation, memory defects, delusions and rages at 66, later mental deterioration with muteness and dysphagia. He died of cardiac failure. The postmortem examination revealed macroscopically and light microscopically the neuropathological findings of atypical senile dementia. Moreover, it is the interesting characteristic in the presented case that there are electron microscopically two types of filaments making the neurofibrillary tangles. One showed the so-called “paired helical filaments”, which were observed in the cerebral cortex. The other showed parallel “straight filaments”. These “straight filaments” were found in the bilateral hippocampi.
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  • 58
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 42 (1978), S. 81-86 
    ISSN: 1432-0533
    Schlagwort(e): Bunina bodies ; Anterior horn cells ; Amyotrophic lateral sclerosis ; Cytoplasmic laminar bodies ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Light and electron microscopic studies were made on the anterior horn cells in a case of amyotrophic lateral sclerosis. Eosinophilic inclusions of Bunina type were observed almost selectively in the motor neurons of spinal cord, as well as of brain stem, at the light microscopic level. Fine structural study revealed the presence of two types of cytoplasmic inclusions. The first, mainly corresponding to the light microscopic inclusions, were homogeneous, electron-dense, round- or oval-shaped bodies with vesicular or tubular rims and ribosome particles, about 2–5 μ in diameter, which contained filaments or other cytoplasmic components in the clear areas within them. The second were lamellar structures (laminated cytoplasmic bodies, Morales) which appeared to be originating from endoplasmic reticulum. There was no distinct transition in these two types of inclusions and the relationship to each other is not clear. The significance of Bunina body is unknown, but some manifestation of a primary disorder, e.g., protein metabolism, rather than a secondary degenerative change in the motor neurons in amyotorophic lateral sclerosis.
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 43 (1978), S. 213-216 
    ISSN: 1432-0533
    Schlagwort(e): Intrafusal muscle fibres ; Pyridoxine ; Neuropathy ; Muscle spindles ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Male albino rats treated with excessive amounts of pyridoxine developed an impairment of neuromuscular function. The equatorial region of the plantar lumbrical intrafusal muscle fibres was studied in the electron microscope and the calibre of the nerve fibres was determined in semi-thin sections of the posterior tibial nerves. Degeneration of the primary sensory endings coincided with the onset of ataxia, and in more advanced stages of the neuropathy as well as after a 2-month treatment-free period the equatorial region was denervated. There was a corresponding decrease in the number of large nerve fibres. It is considered essential that primary sensory endings of lumbrical muscle spindles should be included in studies of distally accentuated sensory neuropathies.
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  • 60
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 43 (1978), S. 251-253 
    ISSN: 1432-0533
    Schlagwort(e): Tick-borne encephalitis ; Serology ; Electron microscopy ; Virus demonstration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case is presented in which the fourfold increase of the HI titer during the progression of the disease, and an increase in IgM content found at the beginning of the second week of the disease confirmed the diagnosis of tick-borne encephalitis. The light microscopic changes corresponded to the findings accepted as characteristic to tick-borne encephalitis. Viruses, morphologically belonging to the Havivirus genus, were found by electron microscopy in the thalamus, substantia nigra, and cerebellum of the dissected brain. This paper presents the first demonstration of the virus in a case of human tick-borne encephalitis.
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 53-56 
    ISSN: 1432-0533
    Schlagwort(e): Blood-brain barrier ; Air embolism ; Horseradish peroxidase ; Cerebral cortex ; Electron microscopy ; Carotid artery ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Male albino rats were anaesthetized with diazepam, injected with horseradish peroxidase and Evans blue-labeled albumin and given an embolus of 0.01 ml air in the right common carotid artery after ligation of the external carotid branch. The pial arteries of the right cerebral hemisphere were stained blue, particularly the middle cerebral artery and its main arterial branchlets. Ultrastructurally, some endothelial cells in the right middle cerebral artery, small arteries and arterioles showed a diffuse distribution of horseradish peroxidase in their cytoplasm, although these vessels only occasionally showed peroxidase in their basement membranes. Other endothelial cells in these arterial branchlets showed few if any signs of a diffuse distribution of peroxidase but displayed several pinocytotic vesicles and occasionally trans-endothelial channels filled with peroxidase, sometimes with a slight leakage of peroxidase into adjacent basement membranes and neuropil. Scattered pinocytotic vesicles were observed in capillaries and venules, but there was usually no extravasation of peroxidase around these vessels.
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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 91-102 
    ISSN: 1432-0533
    Schlagwort(e): Myclin degradation ; Wallerian degeneration ; Optic nerve ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural events in myelin degradation in the rat optic nerve following transection have been studied. Myelin debris was found in cells similar to multipotential glia cells (Vaughn and Peters, 1968) as well as in astrocytes and in few oligodendrocytes. The different types of inclusions found during myelin degradation were described in their quantitative relations. Similarities to inclusions described in adrenoleukodystrophy and multiple sclerosis are discussed. By comparison of the ultrastructural findings with histochemical and biochemical data available a hypothetical model of myelin degradation is presented. The process starts with the degradation of digestible proteins resulting in uniformly layered lipid inclusions. Lipid degradation leads to the formation of unstructured lipid droplets and crystals. During the late stages of Wallerian degeneration numerous polymorph inclusion types can be found, probably representing poorly digestible lipids or lipoproteins.
    Materialart: Digitale Medien
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 44 (1978), S. 229-233 
    ISSN: 1432-0533
    Schlagwort(e): Melanotic tumors ; Neural crest ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A pigmented tumor was removed from the maxillar alveolar process of a 5-month-old boy. It was examined by light and electron microscopy and a diagnosis of melanotic neuroectodermal tumor was made. In addition to connective tissue, three main cell types were identified: undifferentiated (stem) cells, melanocytes, and nerve cells with processes forming an abundant neuropil. Numerous axo-dendritic and occasional axo-somatic synapses were observed. The neural component demonstrated better differentiation in this example than in any reported so far.
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 43 (1978), S. 135-141 
    ISSN: 1432-0533
    Schlagwort(e): Nerve injury ; Perineurium ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The intrafascicular contents have been extracted from the tibial nerve of the rabbit through perineurial incisions. Within 6–8 days following this procedure, the perineurial cells separate from one another, become dissociated from their basement membranes and assume a fibroblast-like appearance. The intrafascicular space becomes populated with endoneurial fibroblasts. With the ingrowth of regenerating axons, bundles of axons and associated Schwann cells become surrounded by cells of fibroblastic appearance which undergo perineurial transformation resulting in the development of multiple small fascicles. The cells of the surrounding perineurium appear to reassume a lamellar organization and to reestablish contacts with each other with the formation of junctional complexes. It is therefore suggested that neural structures may be responsible for the development and maintenance of the structural organization of the perineurium.
    Materialart: Digitale Medien
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    European archives of oto-rhino-laryngology and head & neck 221 (1978), S. 157-162 
    ISSN: 1434-4726
    Schlagwort(e): Gefrierbruchmethode ; Elektronenmikroskopie ; Zonulae occludentes ; Gap junctions ; Limbus spiralis ; Freeze fracture ; Electron microscopy ; Zonulae occludentes ; Gap junctions ; Spiral limbus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Summary Replicas of the freeze fractured spiral limbus are studied in chinchillas. Zonulae occludentes are demonstrated between the interdental cells and the inner sulcus cells; gap junctions are described connecting interdental cells and inner sulcus cells to one another and they are found between the perilymphatic cells in the spiral limbus.
    Notizen: Zusammenfassung Untersuchung des Limbus spiralis an Chinchillas mit Hilfe der Gefrierbruchmethode. Zonulae occludentes werden zwischen den Interdentalzellen und den Zellen des inneren Sulcus demonstriert; gap junctions verbinden die Interdentalzellen und die Zellen des inneren Sulcus miteinander, weiter finden sie sich zwischen den perilymphatischen Zellen des Limbus.
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 33 (1978), S. 353-369 
    ISSN: 1432-1106
    Schlagwort(e): Synaptic development ; Visual system ; Visual cortex ; Superior colliculus ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The development of synapses in the visual cortex (VC) and superior colliculus (SC) of the rabbit has been examined with the electron microscope. In both areas, the number of synapses reaches adult levels by 20–25 days of postnatal age, but the development in the visual cortex is delayed in comparison to that in the superior colliculus. When S synapses (spheroidal vesicles, asymmetric thickening) are compared with F synapses (flattened vesicles, symmetric thickening), even greater differences are seen. In both the VC and SC, S synapses develop earlier than F synapses, though there is considerable overlap. Of interest is the fact that synapses in the visual cortex seem to overshoot their adult levels late in development, suggesting that an excess of synapses may be formed in this system. Multiple synapses, probably of retinal origin, increase in the first 3 weeks of synaptic development in the SC, but never are present in significant proportions in the VC. Synapse formation most often is characterized by formation of a junction and a postsynaptic thickening, followed by acquisition of synaptic vesicles. After 15 days, there is only a small number of such “non-vesicle synapses” in either the SC or VC.
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  • 67
    ISSN: 1432-1106
    Schlagwort(e): Nigrothalamic projections ; Autoradiography ; Electron microscopy ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Light microscopic autoradiography and electron microscopy were used to trace the nigrothalamic projections and to study the sites of termination of this pathway in the cat. Injections of tritiated amino acids or electrolytic lesions were placed in the substantia nigra pars reticularis (SNr). An accumulation of radioactivity was found in the ventral medial nucleus and in the ventromedial part of the ventral anterior nucleus. At the ultrastructural level degenerating medium size synaptic boutons and medium size myelinated fibers were observed in these nuclei. The boutons contained clear pleomorphic vesicles and formed symmetrical type synaptic contacts with regular type dendrites and vesicle-containing dendrites. The present findings indicate that the ventral medial nucleus is the principal site of termination of nigrothalamic projections in the cat.
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Intensive care medicine 4 (1978), S. 181-191 
    ISSN: 1432-1238
    Schlagwort(e): Pulmonary fibrosis ; Electron microscopy ; Fibrinous exudates ; Hyaline membranes ; Treatment with acexamic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Comparative light and electron microscopic studies of the lung were performed in 19 cases of diffuse acute interstitial fibrosis with various etiologies. Our observations emphasize the relation between hyaline membranes (HM) and the evolution of fibrosis. HM formation is due to fibrinous exudates and epithelial necrosis. This phenomenon recurs during the evolution of the disease and appears to be responsible for new waves of fibrosis. Its pathogenesis (humoral or neurovascular ...) remains hypothetical. Modifications of the alveolar epithelium consecutive to septal fibrosis can be clearly distinguished from “fibrinoid necrosis”-type lesions, which result in HM. The formation of HM is accompanied by fibroblastic stimulation which proceeds in spite of epithelial renegeration. The exact stimulus for the proliferation and collagen hypersecretion of fibroblasts remains to be determined. The use, in association with corticosteroid treatment, of a structural analogue of L lysine, acexamic acid, to impede collagenesis reveals encouraging perspectives for improved therapy.
    Materialart: Digitale Medien
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Environmental biology of fishes 3 (1978), S. 185-191 
    ISSN: 1573-5133
    Schlagwort(e): Euthynnus affinis ; Electron microscopy ; Kawakawa tuna ; Red fibres ; White fibres ; Muscle size ; Activity ; Thermogenesis ; Thermal inertia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Synopsis An electron microscopic study of the red and white muscle fibres in the trunk musculature of the Kawakawa tuna (Euthynnus affinis) was carried out with a view to correlating their structure with metabolic adaptation. The red fibres which are considerably smaller in diameter (34.58 μm ± 6.16 S.D.) are characterized by their high content of myoglobin, mitochondria, lipid droplets and glycogen granules. The white fibres which are relatively larger in diameter (66.03 μm ± 11.59 S.D.) are characterized by their lack of myoglobin, low mitochondria) density, high content of glycogen granules and the conspicuous absence of lipid droplets. The characteristics in fine structure of the two fibre types are discussed in the light of their metabolic adaptation, the red fibres as being adapted for long term cruising movement utilizing lipid as the main source of energy and the white fibres for short bursts of activity metabolizing glycogen as the chief fuel. The tuna, with the acquisition of the counter-current heat exchange system which provides for the retention of the heat generated from high substrate oxidation in the red muscle and an efficient respiratory system, it is postulated, is well adapted for high speed sustained swimming.
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    European archives of psychiatry and clinical neuroscience 225 (1978), S. 275-282 
    ISSN: 1433-8491
    Schlagwort(e): Metachromatic leucodystrophy, adult ; Sulfatidosis ; Intracellular storage ; Lamellar inclusions ; Electron microscopy ; Metachromatische Leukodystrophie, adulte ; Sulfatidose ; Intracelluläre Speicherung ; Lamelläre Einschlüsse ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Primär formalinfixierte Gewebsproben aus der entmarkten weißen Substanz des Stirnhirns eines Autopsiefalles von adulter MLD wurden elektronenmikroskopisch untersucht. Das intracelluläre Speichermaterial ließ folgende Strukturmuster-Typen erkennen: (I) Gewöhnliche Myelinfiguren; (II) gefältelte Myelinfiguren; (III) schmale Stapel von scheibchenförmigen Lamellen, die sehr wahrscheinlich Bestandteile von ehemals kompakten „prismatischen“ Einschlüssen waren; (IV) gepaarte Lamellen, entweder in lockerer paralleler Anordnung oder in regelloser Verteilung und Ausrichtung; (V) Schichten von parallel verlaufenden Lamellen mit alternierend dichten und kontrastarmen Zwischenräumen; und (VI) Häufchen von Gebilden, die Bruchstücken von sog. pentalaminären Membranen glichen. Die Typen I bis IV sind sowohl bei Früh-als auch bei Spätformen der MLD schon beschrieben worden, die Typen V und VI dagegen noch nicht. Möglicherweise hatten postmortal-autolytische Vorgänge eine Änderung der strukturellen Organisation von einigen cytoplasmatischen Ablagerungen und die Ausbildung dieser bisher bei der MLD unbekannten Lamellenmuster bewirkt.
    Notizen: Summary Formalin-fixed samples from the demyelinated frontal white matter of an autopsy case of adult-onset MLD were studied by electron microscopy. The intracellular storage materials exhibited the following types of structural patterns: (I) ordinary myelin figures; (II) pleated myelin figures; (III) narrow stacks of lamellar discs which were most likely components of formerly compact ‘prismatic’ inclusions; (IV) paired lamellae, either arranged in loose parallel arrays or scattered about in random directions; (V) piles of parallel lamellae with alternating electron-dense and electron-lucent interspaces; and (VI) collections of structures resembling fragments of so-called pentalaminar membranes. Types I to IV have already been described in early-onset as well as in late-onset forms of MLD, but types V and VI have not. Postmortem autolysis had possibly altered the structural organization of some cytoplasmic deposits and given rise to the formation of those lamellar patterns which were hitherto not known to occur in MLD.
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    European archives of psychiatry and clinical neuroscience 225 (1978), S. 127-134 
    ISSN: 1433-8491
    Schlagwort(e): Toxoplasma gondii ; Toxoplasmosis, cerebral ; Encephalopathy, toxoplasmic necrotizing ; Hodgkin's disease ; Immunosuppression ; Electron microscopy ; Toxoplasma gondii ; Toxoplasmose, cerebrale ; Toxoplasma-Encephalopathie, nekrotisierende ; Morbus Hodgkin ; Immunsuppression ; Elektronenmikroskopie
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Ein 41jähriger Mann verstarb unter progredienter cerebraler Symptomatik, nachdem 11 Jahre ein Morbus Hodgkin bestanden hatte, der mit Röntgenbestrahlungen, Cytostatika und Corticoiden behandelt worden war. Autoptisch fanden sich nicht sehr ausgedehnte Manifestationen der Lymphogranulomatose im Thoraxbereich und multiple käsige Nekrosen im Gehirn. In diesen konnten licht- und elektronenmikroskopisch Toxoplasmen nachgewiesen werden. Die auffallend geringe Intensität der entzündlichen Reaktion im Bereich der Nekroseherde deutete darauf hin, daß sich der Patient in einem immunsuppressiven Zustand befunden hatte. Pathomorphologie und Klinik der cerebralen Erwachsenen-Toxoplasmose werden besprochen. Auf ihr vorzugsweises Auftreten bei konsumierenden Krankheiten, insbesondere bei Morbus Hodgkin, wird nachdrücklich hingewiesen.
    Notizen: Summary A male patient with a history of Hodgkin's disease of 11 years duration died at age 41 with signs of progressive cerebral involvement. The blastomatous process had been treated with X-rays, cytostatic agents, and corticosteroids. Autopsy revealed isolated lymphogranulomatous lesions in the chest walls and multiple foci of necrosis in the brain. In the latter, Toxoplasma could be detected by light and electron microscopy. The inflammatory response elicited by the protozoan parasite was strikingly slight. This indicated that the patient had had some immunologie impairment. Pathomorphologic and clinical aspects of cerebral toxoplasmosis in the adult are discussed. It is emphasized that patients suffering from chronic malignant disorders, particularly Hodgkin's disease, are preferentially affected by toxoplasmosis of the brain.
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 195 (1978), S. 17-27 
    ISSN: 1432-0878
    Schlagwort(e): Myosatellite cells ; Muscles ; Atlantic hagfish (Myxine glutinosa, L.) ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The incidence of myosatellite cells associated with “white” and “red” muscle fibres of the parietal muscle and “red” fibres of the craniovelar muscle was estimated by quantitative electron microscopy in the Atlantic hagfish (Myxine glutinosa, L.). Myosatellite cell nuclei constitute 3, 11 and 23 % of the total number of nuclei inside the basal lamina of the three types of muscle fibres, respectively. However, the total number of nuclei is highest in “white” fibres, most of the nuclei belonging to striated muscle cells. Myosatellite cell profiles in transverse sections constitute 23, 41 and 61 % of the number of muscle fibre profiles of the three types, respectively. The intervals between adjacent myosatellite cells are ∼ 135 μm in “white” fibres, ∼ 55 μm in “red” parietal fibres, and only ∼ 25 μm in craniovelar fibres. Since craniovelar fibres are also comparatively thin, myosatellite cells constitute a significant fraction of the volume inside the basal lamina in these fibres. The myosatellite cells are ∼ 30–50 μm long and up to 5 μm thick. Some myosatellite cells possess few organelles, whereas others appear to contain many free ribosomes, granular endoplasmic reticulum, prominent Golgi apparatus and lysosome-like bodies.
    Materialart: Digitale Medien
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 195 (1978), S. 29-43 
    ISSN: 1432-0878
    Schlagwort(e): Endocrine hypothalamus (rat) ; Arcuate nucleus ; L-dopa ; Autoradiography ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Light and electron microscopic autoradiography has been employed to define the neuroanatomical patterns of uptake and binding of radiolabelled L-dopa in the endocrine hypothalamus of the rat. A dorsomedial continuum of arcuate and periventricular neurons selectively sequester 3H L-dopa 20 min following its intraventricular infusion. By 40 and 60 min following the infusion labelling of neurons is minimal and supports the notion of rapid degradation. Other cell compartments such as tanycytes demonstrate uptake of 3H L-dopa. The ultrastructural localization and distribution of radiolabelled L-dopa (or its metabolites) in the rodent hypothalamus is discussed with respect to mechanisms and cell compartments involved in neuroendocrine regulatory processes.
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  • 74
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 189 (1978), S. 277-286 
    ISSN: 1432-0878
    Schlagwort(e): Maternal adrenalectomy ; Rat ; Influence on the adrenals of newborn animals ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Maternal adrenalectomy at 7 or 14 days of gestation produced increased cell necrosis within zona reticularis cells on the day of birth and at 24 or 48 h after birth. Small remnants or large portions of adrenocortical cells were present within macrophages. In otherwise normal adrenocortical cells, lipid droplets were incorporated within some mitochondria. Autophagocytosis of single mitochondria was observed within adrenocortical cells. Undoubtedly ultrastructural changes represent stimulation of adrenocortical cells in neonatal rats in response to maternal adrenalectomy.
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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 189 (1978), S. 375-388 
    ISSN: 1432-0878
    Schlagwort(e): Lateral line organ ; Pit organ ; Sea eel (Conger myriaster) ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of the pit organ of the sea eel has been studied by means of electron microscopy. The sensory epithelium of the pit organ consists of sensory cells and supporting cells. The apical surface of the sensory cell is studded with sensory hairs consisting of a kinocilium and stereocilia. The sensory cells are divided into two groups. In one, the kinocilium points dorsally and in the other the kinocilium points ventrally. The total number of sensory cells in one pit organ is about 100, and the ratio of cells with opposite polarity is about 1∶1. On the basis of these structural features, the pit organ is considered to be a mechano-receptor sensitive to the movement of liquid in a dorso-ventral direction. It may also serve as an ion receptor, sensitive to environmental ion concentration. Efferent nerve terminals make rare synaptic contacts on the afferent nerve fiber.
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  • 76
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 188 (1978), S. 265-272 
    ISSN: 1432-0878
    Schlagwort(e): Muscles ; T-system ; Fish ; Frog ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In “white” muscle fibres of a teleost fish T-tubule openings may occur regularly at all Z-disc levels between adjacent peripheral myofibrils, the T-tubule openings thus occurring at a density of ca. 0.9 μm-2. In frog “white” fibres, T-tubule openings are infrequently seen in material fixed like the fish material. In material prepared according to the albumin method of Gray (1975, 1976 a, b) which renders the muscle fibres swollen, straight tubules or sometimes chains of vesicles instead are seen opening at the sarcolemmal surface. Such tubules occur at a higher density than expected from experiments with local activation of contraction. Lability and dynamics within the T-system normally and during fixation are discussed.
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  • 77
    ISSN: 1432-0878
    Schlagwort(e): Fertilization ; Membrane fusion ; Male pronucleus ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The apex of the sperm head which has undergone the acrosome reaction comes in contact with the plasma membrane of the ovum. After the entire surface of the inner acrosomal membrane has come into close contact with the plasma membrane of the ovum, the two membranes fuse to form a continuous membrane. All parts of the spermatozoon that are devoid of plasma membrane penetrate into the ooplasm. As the head of the spermatozoon moves deeper into the ooplasm, the chromatin begins to disperse, and the head of spermatozoon is transformed into a large spherical nucleus with low electron density. At a later stage of the transformation, many small vesicles appear around the nucleus and subsequently fuse to form two continuous membranes. These membranes represent the male pronuclear envelope. The condensation of the chromatin occurs in places in the nucleus, so that the male pronucleus is formed. During the course of the formation of the male pronucleus, the subacrosomal rod and tail become detached from the head and disintegrate.
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  • 78
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 191 (1978), S. 187-203 
    ISSN: 1432-0878
    Schlagwort(e): Pituitary ; GTH-cells ; Teleost ; Immunofluorescence ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The gonadotropin-producing cells (GTH-cells) in the Atlantic salmon were studied light and electron microscopically before, during and after spawning, and after injections of luteinizing hormone-releasing hormone (LH-RH). The double immunofluorescent technique was applied using rabbit anti-carp GTH as the first antibody. Numerous immunofluorescent cells were observed throughout the pars distalis, but very few in the pars intermedia. These cells are basophilic and PAS-positive, and ultrastructurally classified as globular gonadotropes. Only one gonadotropic cell type could be identified; its size, morphology and fine structure vary considerably. In the same specimen the GTH-cells can be predominantly globular or vesicular in appearance, depending on the reproductive phase of the fish. At spawning and after LH-RH injection, many GTH-cells reach a vacuolar stage; the content of the vacuoles is not immunofluorescent. Another cell type, which resembles GTH-cells in semithin sections, did not show gonadotropic properties; its nature and functional significance are unknown. In addition, the present study revealed an increase in the synthetic and exocytotic activity of prolactin cells after LH-RH injections. It is suggested that LH-RH mediates this effect via LH and eventually via estradiol.
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  • 79
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 189 (1978), S. 167-177 
    ISSN: 1432-0878
    Schlagwort(e): Hypodermis ; Rotifer ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The integument of the rotifer Habrotrocha rosa Donner is provided with pores and formed by an extrasyncytial cuticle and a syncytial hypodermis. The hypodermis peripherally contains 3 layers of dense cytoplasm and borders the cuticle by an asymmetric cell membrane. The wall of the pores is stiffened proximally like an annulus. The pores lead into cytoplasmic invaginations which are surrounded by vesicles. Close to and also beneath the condensed cytoplasmic layers microbodies are found, which are interpreted as microperoxisomes. Subhypodermal layers of muscles are connected with the cytoplasm of the hypodermis by desmosome-like structures.
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 187 (1978), S. 159-165 
    ISSN: 1432-0878
    Schlagwort(e): Endocrine cells ; Ascidian (Styela clava) ; Gut epithelium ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ultrastructural studies have shown the presence of two types of granulated endocrine cell in the gut of Styela clava. Type I, which occurs in the stomach and intestine contains small irregular granules, each with a distinct halo. Type II, found only in the oesophagus contains larger rounded granules, often with little or no halo. The characteristics of these two cell types are compared with those of endocrine cells found in the digestive tracts of other protochordates and discussed with special reference to the evolution of gastrointestinal endocrine cells in vertebrates.
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  • 81
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 188 (1978), S. 11-18 
    ISSN: 1432-0878
    Schlagwort(e): Purkinje fibers (Ox, goat) ; Axons ; Nerve endings ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The moderator band in the heart of the ox and goat contains bundles of Purkinje fibers and nerve fibers separated by connective tissue. The axons are mostly unmyelinated and embedded in the cytoplasm of Schwann cells. Small bundles of axons run close to the Purkinje fibers. The axons dilate into varicosities 0.5 to 1.6 μ in diameter (mean 0.95 μ), containing three types of vesicles: 1) agranular vesicles with a diameter of 400–500 Å, 2) large dense-cored vesicles with a diameter of 800–1200 Å, 3) small dense-cored vesicles with a diameter of 500 Å. Most varicosities contain agranular vesicles together with a few large dense-cored vesicles. The gap between the varicosities and the nearest Purkinje fiber is unusually wide and normally varies between 0.3 μ and 0.8 μ. No intimate nerve-Purkinje fiber contacts, with a cleft of 200 Å, were observed.
    Materialart: Digitale Medien
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 188 (1978), S. 75-82 
    ISSN: 1432-0878
    Schlagwort(e): Drum muscles ; Piranha ; Degenerative changes ; Fine structure ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the posterior drum muscle of the piranha structural alterations are frequently observed. Electron microscopic studies revealed a disordering of the myofibrils in these regions, accompanied by conspicuous changes in the mitochondria. As the degree of disorder increases, the mitochondrial cristae initially swell to form vesicles. Eventually the mitochondria become filled with myelin-like lamellar structures, which in many cases coalesce to form a dense outer wall. A striking concentration of lysosomes into localized masses was also characteristic of these regions.
    Materialart: Digitale Medien
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  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 188 (1978), S. 497-508 
    ISSN: 1432-0878
    Schlagwort(e): Fertilization ; Domestic fowl ; Acrosome reaction ; Vitelline membrane ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The developing outer layer of the vitelline membrane of the ovum in the posterior part of the infundibulum of the domestic fowl contains many spermatozoa in nearly parallel orientation with its inner layer. When the acrosomal region of a spermatozoon approaches or contacts the inner layer, promptly undergoes the acrosome reaction. The outer acrosomal membrane and overlying plasma membrane fuse together and the apical region of the acrosome opens, so that the acrosomal contents are released. Meanwhile the spermatozoon remains a time in contact with the surface of the inner layer, and the network of the inner layer just under the tip of the sperm head begins to be dissolved. This dissolution extends downward forming a tunnel, approximately 9 μm in diameter. The spermatozoon then passes through the inner layer obliquely via the central region of the tunnel and arrives at the perivitelline space.
    Materialart: Digitale Medien
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  • 84
    ISSN: 1432-0878
    Schlagwort(e): Subfornical organ ; Third ventricle ; 6-Hydroxydopamine ; Electron microscopy ; Primate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The neurotoxin 6-hydroxydopamine (6-OH-DA) has been shown to produces degenerative changes in noradrenergic nerve terminals and preterminals in the CNS following intracisternal, intraventricular, and stereotaxic injection into the brain parenchyma. Systemic injections of this drug are also known to result in degenerative changes in noradrenergic terminals in the peripheral nervous system and in the circumventricular organs (CVO; areas of the CNS which lie outside the blood brain barrier). In the present study eight adult female cynomolgus monkeys were employed. The four experimental animals were injected on two successive days with 150 and 200 mg/kg 6-OH-DA, respectively. The four controls received only the diluent consisting of 0.1% ascorbic acid in normal saline. Two animals from each of the experimental and control groups were sacrificed at 2 h and 24 h after the second injection. Degenerative changes in the SFO neurons were characterized by a generalized increase in electron density of cytoplasmic elements in axonal terminals and preterminals. Multilamellar bodies, and increases in the number of dense core vesicles, dense bodies and secondary lysosomes were also observed after treatment with 6-OH-DA. The neurons showed clumping of mitochondria, which also appeared to be undergoing degenerative changes. The vacuoles in some supraependymal cells were greatly dilated as was the Golgi apparatus in the ependymal cells. The ependymal cell layer appeared to be intact, but there were areas immediately deep to this cell layer that contained large extracellular spaces. This increase in extracellular space was also commonly observed surrounding the perivascular spaces. These phenomena greatly contribute to the “spongy” appearance that the SFO takes on after 6-OH-DA administration.
    Materialart: Digitale Medien
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 191 (1978), S. 171-182 
    ISSN: 1432-0878
    Schlagwort(e): Frontal ganglion ; Periplaneta ; Synaptic contacts ; Immunohistochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The frontal ganglion, part of the stomatogastric nervous system, contains about 60 to 80 neurons, 25 to 30 μm in diameter. A well developed Golgi system, producing dense-core vesicles, lysosomes, multivesicular bodies and dense bodies are abundant. Glia elements are sparsely distributed. Many nerve fibres contain granules of different size and electron density. Five groups of fibres can be distinguished: Fibres with granules of about 200 nm (type A), fibres with granules of about 160 to 170 nm (type B), fibres with granules of about 80 to 100 nm (type C) and those with synaptic vesicles of 50 nm (type D) respectively. A fifth very small type contains neither vesicles nor granules. Special attention was paid to synaptic contacts. The divergent dyad seems to be the main type in the frontal ganglion. Frequently, neurosecretory endings are observed in presynaptic position. Immunocytochemical “staining” of neurosecretory material closely corresponds to the distribution of type A fibres, as observed electron microscopically. Immunoelectrophoresis of extracts from frontal ganglia with polyspecific anti-neurosecretion-serum reveals a single precipitation line, indicating that the immunocytochemical localization of neurosecretory material is due to reaction with a specific as well as a crossreagent antibody.
    Materialart: Digitale Medien
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 191 (1978), S. 357-362 
    ISSN: 1432-0878
    Schlagwort(e): Prothoracic glands ; Insects ; Electron microscopy ; Macromitochondria ; Crystalloid organization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of the prothoracic glands of Spodoptera littoralis was investigated during the first half of the last larval instar. The secretory cells have two types of mitochondria, micromitochondria and macromitochondria. The micromitochondria have rounded to elongated profiles and sometimes branch. They contain lamellar, tubular and also tubulo-vesicular cristae. The macromitochondria appear generally rounded or oval and possess tubular cristae. Many regular parallel membranes appear within macromitochondria. Favorable sections show tubular structures packed in honeycomb fashion. The mitochondrial cristae are in connection with the tubular structures. Honeycomb and parallel membranes increase in number as the size of the macromitochondria increases.
    Materialart: Digitale Medien
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 193 (1978), S. 247-257 
    ISSN: 1432-0878
    Schlagwort(e): Osteoblasts (Chick embryo) ; Golgi complex ; Microtubules ; Colchicine ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Embryonic chick frontal bones were cultured in the presence of colchicine or vinblastine and subsequently examined by transmission electron microscopy. In control cultures the osteoblasts showed a large Golgi complex consisting of dictyosomes arranged in a well-defined juxtanuclear area. Microtubules were particularly numerous within this Golgi area although they could be observed throughout the cytoplasm. Colchicine and vinblastine caused the disappearance of cytoplasmic microtubules, while bundles of 10nm diameter filaments appeared more frequently. In addition, cell polarity was lost and the Golgi complex became disorganized, with the dictyosomes randomly dispersed in the cytoplasm and showing a decreased number of cisternae and an increased number of vacuoles, the latter generally lacking stainable material. Increased number of autophagosomes were also noted. These findings indicate that microtubules function in the organization of the Golgi complex in osteoblasts. In view of the well documented role of this organelle system in collagen secretion it is suggested that previously observed secretory disturbances produced by antimicrotubular drugs may be due to a defective transfer of material to the dictyosomes and/or a defect in the packaging and transport of such material away from them.
    Materialart: Digitale Medien
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 193 (1978), S. 543-560 
    ISSN: 1432-0878
    Schlagwort(e): Human ; Urinary bladder epithelium ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An electron microscopic study of normal bladder urothelium of elderly patients ranging in age from 61 to 82 years has shown the occurrence of unusually thin regions consisting of either one or two layers of undifferentiated cells interspersed between 3–4 cell layers thick regions. A morphometric study has confirmed the existence of a pattern of cytodifferentiation in cells of the thick region. The generally microvillous nature of the luminal surface is attributed to incompletely differentiated cells that have come to occupy the superficial layer. The lack of thickened and/or asymmetric membrane plaques in luminal plasma as well as the dearth of characteristic precursor vesicles in the cytoplasm are also explicable in terms of a failure of normal cell differentiation. It is suggested that the unusual features noted are consequences of tissue ageing rather than prognostic of cancer. There are indications that the aged urothelium may be prone to increased leakiness and the bladder tissues may therefore be at greater risk from urine-borne chemicals and carcinogens.
    Materialart: Digitale Medien
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  • 89
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 194 (1978), S. 79-102 
    ISSN: 1432-0878
    Schlagwort(e): Duodenum ; Endocrine cells ; Differentiation ; Immunocytochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The development and cytodifferentiation of endocrine cells that produce the gastrointestinal hormones gastrin, cholecystokinin and secretin have been studied by a combined fluorescence-cytochemical, immunocytochemical and ultrastructural approach. The results show that, during development, several ultrastructurally distinct cell types exhibit COOH-terminal gastrin and cholecystokinin immunoreactivity. Furthermore, some cells simultaneously contain both gastrin- and cholecystokinin-specific antigenic determinants. Studies on the time course of development of gastrin and cholecystokinin cells, together with the above-mentioned data, suggest that gastrin cells may be converted into cholecystokinin cells in development. During this period, gastrin, cholecystokinin and secretin cells store the biogenic monoamine, 5-hydroxytryptamine a feature not displayed by the adult counter-parts of these cells. In the adult duodenum, characteristic enterochromaffin (EC) cells store 5-hydroxytryptamin for which, evidence for a possible hormonal role has been presented. Taken together, our data indicate that the differentiation of duodenal endocrine cells occurs in distinct steps, each involving a restriction in the biosynthetic repertoire of the cell.
    Materialart: Digitale Medien
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  • 90
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 194 (1978), S. 279-285 
    ISSN: 1432-0878
    Schlagwort(e): 14C-thymidine incorporation ; Autoradiography ; Multinucleated blasts ; Electron microscopy ; Deformities of cellular membranes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cytochalasin B (CB) administered simultaneously with a mitogenic dose of concanavalin A (Con A) interferes with the activation process. This interference involves structural alterations of cellular membrane which do not include a reduced Con A-binding capacity. This conclusion is supported by the observation of deformities in both nuclear and cytoplasmic membranes in Con A-activated lymphocytes subsequently treated with CB. The high incidence of membrane blebs and pseudomyelin bodies in the cytoplasm points to a general effect of CB on the structural organization of membrane which may secondarily interfere with some specific event such as generation or transfer of signals for activation or cytokinesis.
    Materialart: Digitale Medien
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Plant systematics and evolution 129 (1978), S. 135-142 
    ISSN: 1615-6110
    Schlagwort(e): Algae ; Chrysophyceae ; Chrysosphaerella solitaria ; Electron microscopy ; phytoplankton
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new unicellular species of the genusChrysosphaerella (Chrysophyceae) was found in fresh-water ponds in Switzerland, Japan, and the U.S.A. It is described asC. solitaria. The genus is divided into two subgenera:Chrysosphaerella, comprising the colonial species, andPseudochrysosphaerella, the unicellular ones.
    Materialart: Digitale Medien
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 194 (1978), S. 503-511 
    ISSN: 1432-0878
    Schlagwort(e): Cell cultures ; Electron microscopy ; Synaptic organelles ; Spinal cord (mouse)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This study describes some of the ultrastructural features of presynaptic and postsynaptic organelles at synapses developed in cultures of previously dissociated mouse spinal cord cells. Particular attention was paid to the agranular reticulum which is well developed at many presynaptic and postsynaptic sites, either in the form of simple tubules or cisternae, or more complex networks and often closely associated with mitochondria. In addition, the disposition of microtubules at and close to synaptic specializations is described. These and other features of synaptic zones, such as granular vesicles in presynaptic sites, are discussed in relation to cultures developed on feeder layers and synapses in vivo, and in relations to possible degenerative and regenerative events in the cell cultures.
    Materialart: Digitale Medien
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  • 93
    ISSN: 1432-0878
    Schlagwort(e): Guinea pig uterus ; Myometrium, pregnancy ; Sympathetic nerves ; Electron microscopy ; Axon degeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the guinea pig myometrium, the adrenergic nerves selectively demonstrated at the ultrastructural level after treatment with 5-OH-DA, show varying degree of degeneration during pregnancy. The changes are more extensive in a late gestational stage (40–45 days) than in an early one (20–25 days), and are particularly evident in the uterus overlying the conceptus as compared to the regions between the fetuses. Scattered degenerative changes were also observed in myometrial specimens from virgin animals, but probably reflect the normal continuous turnover of axons.
    Materialart: Digitale Medien
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 195 (1978), S. 227-237 
    ISSN: 1432-0878
    Schlagwort(e): Vinblastine ; Lacrimal gland ; Electron microscopy ; Autophagy ; Secretion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of vinblastine treatment on acinar cells of the rat exorbital lacrimal gland were studied by electron microscopy. Experimental animals of both sexes were given single intraperitoneal injections of (1) vinblastine (4mg/kg body weight) at 1 to 24 h before sacrifice; (2) pilocarpine (20 mg/kg b.w.) for 1 h; or (3) vinblastine for l h followed by pilocarpine for 1 h. Vinblastine treatment caused a number of changes including autophagocytosis, formation of intracisternal granules, and alteration of secretory granules. These changes varied in extent and onset between male and female rats. In addition, the Golgi apparatus was reduced in size and dispersed throughout the cytoplasm. Mitotic figures were commonly observed. Moreover, vinblastine inhibited the pilocarpine-stimulated degranulation of the acinar cells. In view of the known anti-microtubular action of vinblastine, these results suggest that microtubules are involved in various aspects of the transport, packaging, and secretion of exportable proteins in the lacrimal gland. Additionally, autophagocytosis and alteration of secretory granules may partially result from the interaction of vinblastine with membranes.
    Materialart: Digitale Medien
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 195 (1978), S. 527-533 
    ISSN: 1432-0878
    Schlagwort(e): Ciliated neurons ; Habenula ; Interpeduncular nucleus ; Electron microscopy ; Rana esculenta, tadpole
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cilia of the 9+2 pattern are found electron microscopically in nonependymal cells of the habenulae and the interpeduncular nucleus of the tadpole of Rana esculenta at an early stage of development (8 mm length, head to tip of tail). A comparison is made between these and the ependymal and sensory cilia in the same specimens. The cilia project into the neuropil emerging from a perikaryon rich in free ribosomes and displaying a prominent Golgi apparatus. These perikarya contain dense core vesicles. Synapses with vesicles of the clear spherical type have been observed along the ciliary shaft. On a purely morphologic basis the authors hypothesize that these cilia, at least in this early ontogenetic stage, may extend considerably the conducting surface of the cell and represent a sensory structure which could be stimulated by terminal processes belonging to distantly located cells. In addition, they could also be involved in the trophic exchange of material with the adjacent structures.
    Materialart: Digitale Medien
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 195 (1978), S. 557-564 
    ISSN: 1432-0878
    Schlagwort(e): Osteoclasts ; Osteocytes ; Bone resorption ; Phagocytosis ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The osteoclast-osteocyte relationship at the endosteal surface of femora of two-week old rabbits was studied. Light microscopic observations suggest that during physiological resorption phagocytosis by osteoclasts of osteocytes takes place. Serial sections confirm that the cells are totally engulfed within the cytoplasm of the osteoclasts. Ultrastructural studies support these findings and indicate that the initial stage of phagocytosis of the osteocytes consists of the insinuation of an extension of the ruffled border into the osteocyte lacuna. These extensions are seen to make close contact with the osteocytes prior to their engulfment by the osteoclasts and their final digestion within phagosomes.
    Materialart: Digitale Medien
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 189 (1978), S. 257-266 
    ISSN: 1432-0878
    Schlagwort(e): Neuromuscular junction ; Hindgut ; Crustacea ; Catecholamine ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The crustacean species Pacifastacus leniusculus and Gammarus pulex were investigated by electron microscopy in a search for possible neuromuscular junctions in the hindgut, which has a rich supply of catecholaminergic fibres. True neuromuscular synapses were found in both species between nerve terminals containing dense-core vesicles (80–110 nm in diam.) and muscle fibres. We suggest that the dense-core vesicle terminals contain a catecholamine, and this is supported by ultrahistochemical tests for monoamines. Two types of junctions are found: one in which the nerve terminal is embedded in the muscle cell (both species) and one in which protrusions from the muscle cell meet nerve terminals (Pacifastacus). Gammarus pulex, which has only circular muscles in the hindgut, has only catecholaminergic innervation, whereas Pacifastacus leniusculus has circular and longitudinal muscles both with at least two types of innervation.
    Materialart: Digitale Medien
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 191 (1978), S. 405-419 
    ISSN: 1432-0878
    Schlagwort(e): Subfornical organ ; Japanese quail, Coturnix coturnix japonica ; Monoaminergic innervation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The parenchyma of the subfornical organ (SFO) of the Japanese quail was studied by light and electron microscopy. The SFO consists of ependymal, intermediate, and basal (perimeningeal) layers. In the intermediate layer, neurons, glial cells, and their processes are found. Axons containing dense core granules approximately 80 nm in diameter are numerous, some of which make synaptic contact with the neuronal perikarya or dendrites. Synaptic vesicles in some axons contain a dense dot in the interior after treatment with 5-hydroxydopamine. The activity of the SFO, which is probably concerned with elicitation of drinking by angiotensin II, may be regulated at least partly by afferent monoaminergic axons. Capillaries with a non-fenestrated endothelium are occasionally found in the parenchyma. The basal layer is occupied by glial processes abutting on the digitating layer of perivascular connective tissue of meningeal vessels. The endothelium of these vessels is occasionally fenestrated. Trypan blue injected systemically accumulated in the SFO, but not in the deeper areas of the brain. The absence of a blood-brain barrier is suggested in the SFO.
    Materialart: Digitale Medien
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 192 (1978), S. 39-51 
    ISSN: 1432-0878
    Schlagwort(e): Prostate ; Rat-Anti-Androgens ; Nuclear alterations ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of the nuclei of epithelial cells of the dorsal lobe of the rat prostate were studied after administration of three different antiandrogenic compounds. The nucleolus appears to undergo a progressive disorganisation with partial fragmentation and dispersion of its normal components. Different types of intranuclear inclusions were found. The various alterations observed were often encountered within the same section. This may indicate that the nuclear alterations occur in the same compartment of the cell, and represent a dysfunction of integrated biochemical events occurring within this compartment. The findings support a view that the stimulatory secretory effect of androgens is mediated via a ‘secretory center’, located within the nucleolusassociated chromatin. Within this ‘secretory center’, the initial steps of the secretory process, the binding of the DHT receptor complex to DNA is assumed to occur.
    Materialart: Digitale Medien
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  • 100
    ISSN: 1432-0878
    Schlagwort(e): T-lymphocytes ; Stereological model system ; Free cells ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Menschliche, in Nylonwolle gereinigte T-Lymphozyten aus dem peripheren Blut dienten als repräsentatives Untersuchungsobjekt zur Schaffung eines neuen stereologischen Modellsystems für freie, sphärische Zellen. Dieses System erlaubt, die Zelle und die darin enthaltenen Strukturkomponenten auf ultrastruktureller Ebene quantitativ zu charakterisieren.
    Notizen: Summary T-lymphocytes derived from human peripheral blood and passed through a nylon-wool column, were employed to develop and test a new Stereological model system for free spherical cells, allowing a quantitative characterization of the cell and its components at the ultrastructural level. Electron micrographs were recorded in a hierarchical manner at three different levels of magnification and subjected to point counting procedures. The resulting parameters were expressed in relation to various reference compartments, both absolute and relative. Results indicated that the average volume of a small, non-activated T-lymphocyte was 103.8 μm3, the nuclear volume 47.5 μm3 and the cytoplasmic volume 55.9 μm3. On the average, the cytoplasm contained 30 mitochondria, 0.7 μm3 RER-cisternae, 0.2 μm3 cisternae and vesicles of the Golgi apparatus and about 231,000 free ribosomes (most of them single). The ratio of eu- to heterochromatin volume was 0.5. The design and application of the Stereological model system are discussed with regard to dynamic studies of a variety of free cells, such as macrophages, neutrophilic granulocytes and various lymphocytes.
    Materialart: Digitale Medien
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