Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1985-1989
  • 1975-1979  (822)
  • 1978  (822)
  • Organic Chemistry  (694)
  • Ultrastructure  (128)
  • 1
    Electronic Resource
    Electronic Resource
    Coquille de l'oeuf de caille: Étude ultrastructurale et cristallographique (1978)
    Springer
    Calcified tissue international 25 (1978), S. 145-159 
    Details
    ISSN: 1432-0827
    Keywords: Bird egg shell ; Ultrastructure ; Calcification ; Electron diffraction ; Microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The egg-shell of Japanese quail was studied by several techniques. Semithin sections (1μm thick) of non-decalcified shell were observed by normal and polarized light microscopy. Thin sections of non-decalcified shell, examined by transmission electron microscopy, permitted us to observe the forms and dimensions of crystals of calcite within different layers of the shell: mammilary layer, layer of cones, palissade layer and surface crystal layer. There appears to be two distinct zones in the layer of cones as well as in the superficial crystal layer. Electron microdiffraction revealed the orientation of calcite crystals in the columns. Some crystal defects (twins?) were described and the possibility of their artefactual formation during ultramicrotomy is discussed. Localization of Ca, Mg, P and S were made by X-ray microanalysis of semithin sections. This technique shows that shell membranes, and chiefly the true cuticle, are also mineralized but, in these layers, minerals are not crystallized. Otherwise the distribution of Mg is not uniform throughout the shell thickness; it is less concentrated in the external zone of the layer of cones. These results together with observation of developing shells by scanning electron microscopy allowed us to propose a scheme for shell organization of the quail egg. This organization was related with decalcification which occurs during hatching.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010763
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The endocrine pancreas in chronic pancreatitis (1978)
    Springer
    Virchows Archiv 377 (1978), S. 157-174 
    Details
    ISSN: 1432-2307
    Keywords: Pancreatic diabetes ; Endocrine pancreas ; Islet composition ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The endocrine pancreatic tissue from patients with severe primary chronic pancreatitis (n=6), secondary chronic pancreatitis due to duct obstruction by carcinoma (n=6) and non-diabetic, non-pancreatitic controls (n=4) was studied qualitatively and quantitatively using specific immunocytochemistry and electron microscopy. Grouping of variously sized islets in the sclerotic tissue (sclerosis islets), islet neoformation by ductuloinsular proliferation, and intrainsular fibrosis were the main qualitative findings. Immunocytochemical quantitation of the distribution of insulin (B), glucagon (A), somatostatin (D) and pancreatic polypeptide (PP) producing cells revealed a significant relative increase in the number of A cells and a decrease in the number of B cells of the sclerosis islets in primary chronic pancreatitis (B-44.1±9.3%:A-38.3±2.4%:D-8.6±5.1%:PP-4.6±4.1%) as well as in secondary chronic pancreatitis (B-38.0±14.3%:A-38.4±19.0%:D-9.1±5.8%:PP-14.5±23.4%) compared with controls (B-71.1±8.1%:A-24.3±5.5%:D-8.0±2.8%:PP-0.5±0.4%). The number of PP cells was significantly increased in primary chronic pancreatitis only. It is suggested that scarring of the exocrine pancreas affects islet composition, probably by impairment of the local circulation and of glucose diffusion, thus leading to reduction of the number and glucose sensitivity of B cells. The hyperplasia of A and PP cells appears to be a secondary phenomenon due to the loss of B cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427003
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ultrastructure and morphometry of ACTH-producing cell in the rat anterior pituitary gland stimulated by lysin-vasopressin and prostaglandin E1 (1978)
    Springer
    Virchows Archiv 378 (1978), S. 23-33 
    Details
    ISSN: 1432-2307
    Keywords: Pitutary ; Ultrastructure ; Vasopressin ; Prostaglandin ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ziel dieser Untersuchung war es, quantitative and qualitative Änderungen der ACTH-Zelle in der Rattenhypophyse nach Gabe eines spezifischen und eines unspezifischen Stimulus zu untersuchen. Es wurden ein CRF-Analogon (Lysin-Vasopressin) und ein Prostaglandin (Prostaglandin E1) benutzt. Jeweils 20 Ratten wurden für 4 Wochen Lysin-Vasopressin oder Prostaglandin E1 intraperitoneal injiziert. Die Hypophysen wurden licht- und elektronenoptisch sowie morphometrisch untersucht. Nach Gabe beider Stoffe konnte man eine Aktivierung der ACTH-Zellen beobachten. Die Vergrö\erung des Kerns, des Cytoplasmas und der an der Hormonherstellung beteiligten Zellorganellen lie\ sich morphometrisch nachweisen, wobei die Wirkung von Lysin-Vasopressin ausgeprÄgter war als die des Prostaglandins. Darüber hinaus konnte eine Zunahme der ACTH-Zellzahl gefunden und mit einem statistischen Test als signifikant nachgewiesen werden. Im Gegensatz zu Lysin-Vasopressin erstreckte sich die Wirkung des Prostaglandins auch auf andere Hypophysenzellen.
    Notes: Summary The aim of this study was to investigate the qualitative and quantitative changes of ACTH-cells in the rat after application of a specific and a non-specific stimulus. A CRF-analog (lysin-vasopressin) and a prostaglandin (prostaglandin E1) were used. 40 rats were injected lysin-vasopressin or prostaglandin E1, respectively, for 4 weeks. The pituitary glands were investigated by means of light microscopy, electron microscopy and morphometry. Activation of the ACTH-cells could be observed after use of both substances, the effect of lysin-vasopressin being more intense than that of prostaglandin E1. Enlargement of the nucleus, the cytoplasm and the organelles involved in hormone-production and -transport were found and verified by morphometry. Additionally an increase in number of the cells could be demonstrated. Prostaglandin influenced not only ACTH-cells, but also other cells of the anterior pituitary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427183
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    An ultrastructural study of the placenta in materno-fetal rhesus incompatibility (1978)
    Springer
    Virchows Archiv 379 (1978), S. 229-241 
    Details
    ISSN: 1432-2307
    Keywords: Placenta ; Ultrastructure ; Rhesus incompatibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electronoptical study has been made of eleven placentae from cases of materno-fetal rhesus incompatibility. The characteristic findings are focal, but sometimes quite extensive, syncytial necrosis, retention of normal pinocytotic and secretory activity in the non-necrotic syncytiotrophoblast, cytotrophoblastic hyperplasia, thickening of the trophoblastic basement membrane, immature-type endothelial cells in the fetal villous vessels and thickening or lamination of the capillary basement membranes. The pathogenesis of many of these changes is not clear but there is no evidence that they are immunologically mediated. It is suggested that the syncytial necrosis may be due to narrowing of the intervillous space as a result of increased villous size, that the cytotrophoblastic hyperplasia is a response to the syncytial damage and is responsible for the changes in the trophoblastic basement membrane and that the fetal capillary changes are indicative of endothelial cell damage due, possibly, to fetal anaemia. Despite the damage suffered by the placenta in materno-fetal rhesus incompatibility there is little evidence of impaired functional efficiency.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432638
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Chemodectoma of the larynx (1978)
    Springer
    Virchows Archiv 378 (1978), S. 161-172 
    Details
    ISSN: 1432-2307
    Keywords: Chemodectoma ; Larynx ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present case report is concerned with a clinico-pathological study, including ultrastructural investigation, of a rare and uncommon laryngeal tumour, a chemodectoma, in a 62 year old patient. There have been 23 cases of laryngeal chemodectomas reported in the literature, and only three of them, including our own report, were investigated by electron microscopy. The tumours arise from the superior and inferior laryngeal nonchromaffin paraganglia or possibly from Kultschitzky-cells of the normal bronchial mucosa. Ultrastructurally they have all the characteristics of apudomas whose parent cells (the APUD-cells), usually show endocrine function and probably have their origin in the neural crest. The tumours show an aggressive type of behaviour, despite usually benign histological features when compared to chemodectomas at other sites in the head and neck region. Surgery is thus the therapy of choice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432360
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Giant cell tumor of bone (1978)
    Springer
    Virchows Archiv 378 (1978), S. 287-295 
    Details
    ISSN: 1432-2307
    Keywords: Giant cell tumor ; Ultrastructure ; Alkaline phosphatase ; Human bone neoplasias
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structural localization of nonspecific alkaline phosphatase was elucidated in two giant cell tumors of bone using lead as capturing ion and Β-glycerophosphate as substrate in the incubation solution. Lead phosphate precipitate — indicating presence of alkaline phosphatase — was demonstrated on the plasma membranes, and the membranes bordering vesicles and vacuoles of presumed endocytotic nature, in giant cells and type 1 stromal cells (fibroblast-like cells). The findings support the view that stromal cells type I and giant cells are histogenetically related.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00465595
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The ultrastructure of bone cells and bone matrix in human primary hyperparathyroidism (1978)
    Springer
    Virchows Archiv 379 (1978), S. 11-23 
    Details
    ISSN: 1432-2307
    Keywords: Primary hyperparathyroidism ; Bone cells ; Bone matrix ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscope investigation has been carried out on needle biopsies of the iliac crest of 8 patients suffering from primary hyperparathyroidism. A marked increase in bone resorption was the most conspicuous finding. It was due both to increased osteoclastic activity and to periosteocytic osteolysis. The osteoclasts had a more strongly developed brush border and contained more cytoplasmic vacuoles than those in controls. Many osteocytes were found within enlarged, irregular lacunae, and were surrounded by a space containing amorphous, granular and filamentous material. Their mitochondria were sometimes calcified. Osteoblasts were more active than in controls as shown by the developed rough ergastoplasmic cysternae and thick osteoid borders found near some of them. The osteoid tissue, however, was uncalcified; ultrastructurally, lack of the calcification front and incomplete matrix calcification were demonstrable. Mast cells, and osteoclast- and macrophage-like giant cells were often found in the fibrotic marrow spaces. These results confirm that both the resorption and the formation of bone are stimulated in hyperparathyroidism. The calcification process is delayed and often remains incomplete.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432779
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Malignant giant cell tumor of bone (1978)
    Springer
    Virchows Archiv 379 (1978), S. 185-201 
    Details
    ISSN: 1432-2307
    Keywords: Giant cell tumor ; Ultrastructure ; Acid phosphatase ; Lysosomes ; Bone tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of the different cell types constituting a primary malignant giant cell tumor of bone has been studied and the localization of acid phosphatase in relation to the subcellular organelles been demonstrated. Three distinct cell types with characteristic ultrastructural features were observed: giant cells, fibroblast-like cells, and cells with abundant lipid inclusions and mitochondria. Certain differences were noted between these three cell types and their counterparts in benign giant cell tumors of bone (described in a separate report). The enzyme histochemical and morphological data suggested that the giant cells in the malignant tumor might possess a more active and expansive lysosomal apparatus than corresponding cells in the benign variant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432635
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Pinguecula et pterygion: étude histopathologique et ultrastructurale (1978)
    Springer
    Virchows Archiv 379 (1978), S. 321-333 
    Details
    ISSN: 1432-2307
    Keywords: Pinguecula ; Pterygium ; Histology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two pingueculae combined with pterygia were studied by light and electron microscopy. Hyaline degeneration of the collagen, dark staining granular, von Kossa negative concretions and elastotic material were observed in both conditions together with marked changes in the fibroblasts, endothelial cells, pericytes and the basement membrane of conjunctival capillaries and small veins. The elastotic material is similar to that observed in solar elastosis, where the collagen fibers are less severely damaged. Chronic sun exposure of the pericorneal conjunctiva may damage endothelial cells primarily and disturb vascular exchanges. This would result in accelerated degeneration and regeneration of endothelial cells, in thickening of the basement membrane and, secondarily, disturbed metabolism of fibroblasts with alterations of the collagen and elastic fibers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464475
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Ribosome-submembranous density complex (1978)
    Springer
    Acta neuropathologica 44 (1978), S. 249-250 
    Details
    ISSN: 1432-0533
    Keywords: Organelle complex ; Ribosomes ; Meningioma (malignant) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural study of a malignant meningioma revealed an organelle complex composed of: (1) A band-like densification of the cell cytoplasm adjacent to and in contact with the cell membrane. (2) An arciform filament immediately subjacent to it, with concavity directed away from the cell membrane. (3) A row of regularly spaced ribosomes located in the concavity, but at some distance from the arciform filament. (4) A pericellular condensation of interstitial ground substance. Occasionally, a second, thinner filament was seen “threading” the ribosomes together. Its morphology was consistent with that described for messenger RNA. It is suggested that the ribosomes are engaged in the synthesis of proteins for other portions of the organelle complex and that the ultimate role of the specialized unit would be that of an attachment device.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691076
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Studies on the liver of Xenopus laevis (1978)
    Springer
    Anatomy and embryology 154 (1978), S. 1-25 
    Details
    ISSN: 1432-0568
    Keywords: Bile canaliculus ; Development ; Glycogenesis ; Hepatocytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural changes during development and metamorphosis in the liver ofXenopus laevis have been investigated. In this species it was found that developmental processes, which ultimately lead to the formation of bile canaliculi, can be detected in the liver anlage as early as stage 35. While the wall of the primary liver cavity is thrown into folds which form the liver parenchyma, the bile canaliculi are formed (st. 36–38). Secretion into the lumen of the bile canaliculi was not found to occur before stage 47 and IDP-ase activity could not be detected in the bile canaliculi before stage 49. The intra- and extrahepatic portions of the hepatic duct system were found to be formed during the stages 40–41. The formation of the duct system involves cellular degeneration in the lumen of the future ducts. These processes are described in detail. The glycogen content of the developing hepatocytes received particular attention during the course of this study. It was found that after depletion of the embryonal glycogen the hepatocytes are completely free from glycogen during the stages 43–45. At stage 46, after the begin of feeding, beta as well as alpha particles of glycogen appear in the hepatocytes. These first reappearing glycogen particles are formed without the participation of SER membranes, in areas which are loaded with RNA particles. It was found that only after the synthesis of glycogen had been initiated SER membranes started to proliferate in the hepatocytes, where they were mostly found intermingled with glycogen particles. From stage 54 on, where the liver glycogen content was found to be 0.2%, the glycogen content of the liver almost continuously increased until it reached a temporary peak of 10% at the end of metamorphosis. These findings strongly contrast results reported for other amphibia, which at the end of metamorphosis have depleted their glycogen content completely. Details of the ultrastructural changes occuring during development of the hepatocytes, are also reported in this paper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317951
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    The ependymal and glial configuration in the spinal cord of urodeles (1978)
    Springer
    Anatomy and embryology 154 (1978), S. 67-82 
    Details
    ISSN: 1432-0568
    Keywords: Urodeles ; Spinal cord ; Ependyma ; Glia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The structural organization of the ependymal and macroglial components of the central field of the spinal cord of postmetamorphic ribbed newts has been reinvestigated using elaborate fixation procedures for transmission electron microscopy. All along the central canal, the ependymal cells display ultrastructural features that strongly suggest a secretory activity. Infrequent mitotic images, occurring spontaneously among the ependymal cells, were observed. The tightly compacted periependymal stratum contains two types of glial cells: 1. oligodendrocytes, also observed outside this stratum as neuronal satellites, and 2. radial astrocytic cells, whose somata, exclusively located in the periependymal stratum, send their processes to the subpial lamina. The intercellular relationships between ependyma, oligodendrocytes and astrocytic cells are illustrated to show the continuity of the neuroepithelial configuration. Morphologic clues for identifying the cells of the central field of the urodele spinal cord are given. A gradient of differentiation of the oligodendroglial components could be postulated. In normal conditions, the astroglial differentiation is permanently arrested at the stage of radial glia. Some considerations concerning regeneration in the urodele spinal cord are submitted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00317955
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Ultrastructural study of the adenohypophysis of the male Chinese quail (1978)
    Springer
    Anatomy and embryology 154 (1978), S. 185-211 
    Details
    ISSN: 1432-0568
    Keywords: Adenohypophysis ; Cellular types ; Ultrastructure ; Birds ; Excalfactoria chinensis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural analysis of the adenohypophysis in the male Chinese quail reveals seven different types of granular cells, and agranular folliculo-stellate cells. The cell types are assumed to be endocrine cells and are classified as: Type I cells (presumptive LH-gonadotrophs), with dilated endoplasmic reticulum, perinuclear spaces, and granules of 150–260 nm; Type II cells (presumptive FSH-gonadotrophs), with regularly-shaped cytoplasmic cisterns and small granules (80–150 nm); Type III cells (presumptive thyrotrophs), very close in appearance to the type II cells of normal birds; Type IV cells (presumptive prolactin cells), with very large secretory granules (up to 400 nm), Type V cells (presumptive corticotrophs), with abundant and electrondense granules (160–300 nm); Type VI cells, with irregularly-shaped granules; Type VII cells (presumptive somatotrophs), with abundant granules (130–220 nm) and less cytoplasmic structures. Cytological characteristics of the nucleus, and more particularly the presence of a Feulgen-positive nucleolus with a very particular ultrastructure are here reported. It is proposed that heterospecific associations of Chinese quail cells with chick cells can be used in embryological work for the study of cellular interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00304662
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Collagen metabolism in granulating wounds of rat skin (1978)
    Springer
    Archives of dermatological research 263 (1978), S. 207-214 
    Details
    ISSN: 1432-069X
    Keywords: Wound healing ; Collagen metabolism ; Collagen degradation ; Fibroblasts ; Ultrastructure ; Wundheilung ; Kollagenstoffwechsel ; Kollagenabbau ; Fibroblasten ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Kollagenstoffwechsel in granulierenden Hautwunden der Ratte wurde mittels biochemischer, tracerkinetischer und elektronenmikroskopischer Methoden untersucht. Die Ablagerung von Kollagen in Hautwunden der Ratte war nicht nur das Ergebnis eines Anstiegs der Kollagensynthese, sondern wurde ebenso durch eine Abnahme des Kollagenabbaus bedingt. Unsere Ergebnisse zeigten signifikante Unterschiede im Kollagenumsatz zu verschiedenen Zeiten der Wundheilung. Der herabgesetzte Kollagenkatabolismus in den frühen Stadien der Wundheilung steuerte in entscheidender Weise zur Kollagenakkumulation im Wundgebiet bei. Während späterer Stadien, zum Zeitpunkt der Wundkontraktion und der Remodellierung der Narbe, stieg die Umsatzrate des Kollagens an. Die dargestellten Ergebnisse werden im Zusammenhang mit den allgemeinen Kriterien der Narbenbildung diskutiert.
    Notes: Summary Collagen metabolism in granulating wounds of rat skin was studied with biochemical, isotopic and electron microscopical methods. Deposition of collagen in rat skin wounds was not only the result of an increase in collagen synthesis but it was also caused by a decrease in collagen degradation. Our investigations showed significant differences in the collagen turnover at different times of wound healing. Decreased collagen catabolism at the early stages of wound healing contributed decisively to collagen accumulation in the wound area. At later stages, during wound contraction and remodelling of the scar, the rate of collagen degradation rose. The above-mentioned results are discussed in the context of general criteria of scar formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446442
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Elektronenmikroskopische Untersuchung am cutanen Leiomyosarkom (1978)
    Springer
    Archives of dermatological research 263 (1978), S. 159-169 
    Details
    ISSN: 1432-069X
    Keywords: Leiomyosarcoma of the skin ; Ultrastructure ; Cellular differentiation ; Accumulation of centrioles ; Cutanes Leiomyosarkom ; Ultrastruktur ; celluläre Differenzierung ; multiple Centriolen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine 61jährige Patientin hatte sich vor 15 Jahren einen Tumor vom linken Unterschenkel entfernen lassen. Im Bereich der Narbe kam es zu erneuter Tumorbildung. Die histologische Untersuchung zeigte einen aus meist spindeligen Zellen zusammengesetzten Tumor mit vielen Mitosen und Kernpolymorphie. Die Diagnose eines cutanen Leiomyosarkoms wurde durch den elektronenmikroskopischen Nachweis der für glatte Muskelzellen charakteristischen Zellelemente gesichert. Der Differenzierungsgrad der Tumorzellen variierte zwischen relativ differenzierten, filamentreichen Zellen, die noch an normale glatte Muskelzellen erinnerten, und ödematösen, filamentarmen, aber organellenreichen entdifferenzierten Zellen. Eine auffallende morphologische Besonderheit war der wiederholte Nachweis von zahlreichen akkumulierten Centriolen.
    Notes: Summary A 61-year old woman developed a tumourous nodule in her left leg. Fifteen years ago a similar tumour had been removed in the same localization. Histological examination performed on biopsy material showed bundles of predominantly fusiform tumour cells with nuclear pleomorphism and many mitotic figures. Electron microscopic examination confirmed the diagnosis of leiomyosarcoma by demonstration of the ultrastructural characteristics of smooth muscle cells. Cellular differentiation showed various degree ranging from smooth muscle cell type to dedifferentiated edematous tumour cells with scanty myofilaments. An important finding was the demonstration of multiple accumulated centrioles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446437
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Vergleichende Untersuchungen bei juvenilem und adultem Colloid Milium (1978)
    Springer
    Archives of dermatological research 261 (1978), S. 231-244 
    Details
    ISSN: 1432-069X
    Keywords: Colloid Milium ; Different types ; Histopathology ; Ultrastructure ; Colloid Milium ; Verschiedene Typen ; Histopathologie ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Unterschiede im Verlauf und Erbmuster des Colloid Milium deuten an, daß zwischen dem juvenilen und adulten Typ dieser Dermatose wesentliche Unterschiede bestehen. Ziel der vorliegenden Untersuchungen war, mit Hilfe von Licht-, Immunfluorescenz- und elektronenoptischen Methoden nach Unterschieden im mikroskopischen Bereich anhand je eines Falles zu suchen. Folgende Befunde wurden erhoben: Beim juvenilen Colloid Milium sind die Kolloidmassen nicht nur direkt unter dem Epithel abgelagert, sondern auch innerhalb der Epidermis häufig zu finden. Sie zeigen nach Kongorotfärbung einen Dichroismus und können Immunglobuline, Komplement und Fibrin enthalten. Elektronenmikroskopisch zeigt sich, daß sie aus dicht gepackten wellig verlaufenden Fibrillen bestehen, deren individueller Durchmesser etwa 80 Å beträgt. Innerhalb dieser fibrillären Massen sind häufig Melanosomen, Reste von Kernen und anderen Zellorganellen sowie Desmosomen nachweisbar. Beim adulten Colloid Milium sind die Kolloidmassen meist von der Epidermis durch einen Elastika-positiven Bindegewebsstreifen getrennt. Mit Kongorot sind sie nur schwach darstellbar und zeigen keinen Dichroismus. Fluorescenzoptisch zeigen sie eine bläuliche Autofluorescenz, aber keine spezifischen Ablagerungen. Elektronenmikroskopisch kann das adulte Kolloid als feingranuläres Material mit wenigen feinsten Mikrofibrillen charakterisiert werden, das in enger Nachbarschaft von Gefäßen mit verdichteter Basalmembran und von aktiven Fibroblasten gelegen ist. Auf Grund dieser Unterschiede können der juvenile und adulte Typ des Colloid Miliums klar auch mikroskopisch voneinander differenziert werden. Die Ergebnisse deuten darauf hin, daß beim juvenilen Typ vorwiegend epidermale Läsionen, beim adulten jedoch dermale Störungen eine wesentliche Rolle in der Pathogenese spielen.
    Notes: Summary Two different types of colloid milium are characterized on the basis of clinical and genetical parameters. In order to establish morphological criteria allowing a differentiation also at microscopic levels comparative histopathological, histo- and immunochemical as well as ultrastructural investigations were performed in a case of juvenile and a case of adult colloid milium. The following results were obtained: In juvenile colloid milium the colloid material is deposed in direct apposition to the basal epidermal layers and can be found also in suprabasal position within the epidermis. No actinic elastosis is present in the periphery of the deposits but they exhibit a green birefringency by investigation of Congo-red stained frozen sections in polarized light. Immunoglobulins, complement and fibrin can be demonstrated within the deposits by direct immunofluorescence. Electron microscopy reveales a fibrillar ultrastructure of the colloid masses, which contain numerous melanin granules and desmosomes. Therefore the colloid material in the juvenile type is most likely of epidermal origin. In adult colloid milium the colloid is usually separated from the epidermis by a band of connective tissue elements containing a considerable amount of elastin. The surrounding superficial dermis frequently exhibits elastotic changes. Congo-red reaction is only weakly positive and no dichroisms can be found. Direct immunofluorescence reveals no specific staining, but a blue autofluorescence of the material. Ultrastructurally, the adult colloid represents mainly finely granular material, with only few microfilaments. The masses are situated in the dermis, often near duplicated vascular basement membranes and in close apposition to active fibroblasts. Thus, the colloid material seems to be of dermal origin. The microscopic findings strongly indicate, that the two different types of colloid milium indeed represent different entities, discernable not only by clinical or genetic but also by histomorphologic parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00455291
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Action of the “nude” gene on pigmentation of the coat in C57 black and C3H mice (1978)
    Springer
    Archives of dermatological research 262 (1978), S. 219-227 
    Details
    ISSN: 1432-069X
    Keywords: Nude mice ; Skin pigmentation ; Ultrastructure ; Tyrosinase activity ; Hair cycle ; Nackte Mäuse ; Hautpigmentierung ; Ultrastruktur ; Tyrosinaseaktivität ; Haarcyclus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Autoren untersuchten die Pigmentveränderungen an Haut und Haar an pigmentierten nackten Mäusen. Histologische und elektronenmikroskopische Untersuchungen und die Polyacrylamid-Elektrophorese der Tyrosinaseaktivitäten zeigten vom morphologischen und biochemischen, daß die Veränderungen der Programmierung solcher “nude” Mäuse auf den Haarcyclus und auf das Haarwachstum bezogen werden kann. In der Tat entwickeln sich die Haarfollikel cyclisch wie die der Mäuse mit normaler Haut. In depigmentierter Haut waren die Haare in der Ruhepause und es konnte keine lösliche Tyrosinase aufgefunden werden.
    Notes: Summary The authors have studied pigmentary changes of skin and hair due to the presence of the “nude” gene in pigmented species (C 57 Bl. 6J, C 3H). Morphological (histology, electron microscopy) and biochemical (polyacrylamide gel electrophoresis of tyrosinase activities) studies showed that the pigmentary alterations of the “nude” mice were related to the hair cycle and hair growth wave pattern. In fact, in the “nude” mice the hair follicles evolves cyclically similarly to mice of normal coat. In depigmented skin, the hair follicles were in the resting phase and no soluble tyrosinase could be demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00455393
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Pseudolymphoma of skin induced by oriental hornet (Vespa orientalis) venom (1978)
    Springer
    Archives of dermatological research 262 (1978), S. 135-141 
    Details
    ISSN: 1432-069X
    Keywords: Pseudolymphoma ; Oriental hornet venom ; Ultrastructure ; Pseudolymphoma ; Orientalische Wespe ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine einmalige sucutane Injektion des Giftes der orientalischen Wespe führt bei schwarzen Mäusen zu der Entwicklung eines subcutanen Knötchens, welches sich über 1 Jahr hält. Ultrastrukturell zeigt sich eine Anreicherung von Lymphocyten und Lymphoblasten und einige Plasmazellen mit Russelkörperchen. Zusätzlich werden einige Melanin enthaltende Makrophagen und auch solche mit aufgenommenen cellulären Abbauprodukten beobachtet. Die gesamte Reaktion wird mit anderen pseudolymphomatösen Reaktionen in der Haut in Beziehung gesetzt.
    Notes: Summary A single subcutaneous injection of Oriental hornet venom into black mice led to the development of a subcutaneous nodule which showed no change during the period of 1 year. Study of the ultrastructure revealed an accumulation of lymphocytes and lymphoblasts and a few plasma cells with formation of Russel bodies. In addition, a few melanin-containing macrophages and macrophages filled with cellular debris were found. This reaction is compared to other pseudolymphomatous reactions in the dermis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00455382
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    The ultrastructure of mycobacterium marinum granuloma in man (1978)
    Springer
    Archives of dermatological research 262 (1978), S. 205-217 
    Details
    ISSN: 1432-069X
    Keywords: Mycobacterium marinum ; Ultrastructure ; High-turnover granuloma ; Immunogenic orgin ; Intracellular collagen precursor ; Mycobaterium marinum ; Ultrastruktur ; High-turnover Granulom ; Immunogenes Granulom ; Intracelluläre Kollagenpräcursoren
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Drei Knoten (klinisches Alter 3–5 Wochen) von 2 Patienten mit sogenannten Swimmingpool- oder Aquariumgranulomen wurden elektronenoptisch untersucht. Das cytohistologische Spektrum umfaßt sowohl akute exsudative, als auch chronische proliferative Entzündungszeichen. Bereits im 3 Wochen alten Granulom sind Epitheloidzellen und Kollagen produzierende Fibroblasten nachweisbar. Das Mycobacterium marinum-Granulom stellt gemäß dem cytologischen Aufbau ein sog. High-turnover Granulom mit allergischer Genese dar. Es entspricht damit mycobacteriellen Dermatosen bei bestehender guter Abwehrlage (Lupus vulgaris, tuberkuloide Lepra). In Abbau befindliche Mycobacterien konnten in wenigen Phagocyten entdeckt werden. Die Ultrastruktur des lebenden Erregers wird vergleichsweise von tierexperimentellem Material präsentiert. Geschwungene und ringförmige parallele Membranen (“Worm-like structures”) wurden im Cytoplasma von transformierten Makrophagen und in Fibroblasten beobachtet. Fadenförmige quergebänderte Strukturen (Periodizität 170–180 Å) im Lumen des rauhen endoplasmatischen Reticulums von einigen Fibroblasten werden als intracellulär aggregierte Kollagenpräcursoren interpretiert.
    Notes: Summary 3 biopsies of 3–5 week-old nodular lesions in 2 patients with socalled swimming-pool (aquarium-) granuloma have been examined by electron microscopy. The cytohistological spectrum simultaneously comprises acute exudative as well as chronic proliferative phenomena. Epithelioid cells and collagen producing fibroblasts already conspicious in 3 week-old granuloma. According to the cytological composition the Mycobacterium marinum granuloma represents a high-turnover granuloma with immunogenic origin. It is comparable to mycobacterial diseases in the presence of well developed cell mediated immunity (Lupus vulgaris, tuberculoid leprosy). Degrading mycobacteria have been rarely detected in phagocytes and are compared with viable bacilli in macrophages of experimentally infected mice. Curved and annular parallel membranes (“worm-like structures”) in the cytoplasm of transformed macrophages and in fibroblasts presumably originate from the membranes of endoplasmic reticulum. Cord-like structures with transverse bands (periodicity 170–180 Å) in the lumen of RER of some fibroblasts are interpreted as intracellularly aggregated collagen precursors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00455392
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Ultrastructural detection of Haemophilus ducreyi in biopsies of chancroid (1978)
    Springer
    Archives of dermatological research 263 (1978), S. 153-157 
    Details
    ISSN: 1432-069X
    Keywords: Chancroids ; Biopsies ; Haemophilus ducreyi ; Ultrastructure ; Ulcera mollia ; Biopsien ; Haemophilus ducreyi ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Anläßlich einer lokalen Häufung von insgesamt 26 Ulcus molle-Fällen in Berlin (West) wurden in Biopsien coccoide Stäbchen durch ultrastrukturelle Untersuchung entdeckt. Ihre Zellwand ist ca. 120 Å dick und trilaminar entsprechend Gram-negativen Bakterien. Die Bakterien sind hinsichtlich der Zellwandstruktur sowie der Cytoplasmazusammensetzung identisch mit Haemophilus ducreyi, die kulturell von typischen Ulcera mollia gezüchtet, intermittierend mikroskopisch auf Reinheit geprüft, in tierisches Material geimpft und anschließend ultrastrukturell untersucht wurden. In menschlichem ulcerösen Gewebe finden sich die Bakterien überwiegend im Extracellulärraum und in Gruppen gelagert.
    Notes: Summary During an endemic appearance of chancroids (26 cases) in Berlin (West) coccobacilli were disclosed in biopsies by electron microscopy. The bacteria were aggregated predominantly in groups in the extracellular space. Their cell wall is approximately 120 Å thick and trilaminar as in Gram-negative bacteria. Concerning the cell wall structure and the cytoplasmic composition, the detected coccobacilli are identical to culturally grown Haemophilus ducreyi obtained from chancroids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446436
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Étude en microscopie électronique et par cytophotométrie à balayage de la structure et de la distribution de la chromatine dans les noyaux des cellules cartilagineuses deTriturus cristatus âgés au cours de la régénération (1978)
    Springer
    Development genes and evolution 184 (1978), S. 195-211 
    Details
    ISSN: 1432-041X
    Keywords: Ultrastructure ; Scanning cytophotometry ; Chromatin ; Chondrocytes ; Regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les cellules cartilagineuses des membres postérieurs deTriturus cristatus en régénération après amputation, ont été étudiées en microscopie électronique et par cytophotométrie à balayage. Nous nous sommes intéressés à la structure et à la distribution de la chromatine mais aussi à différents organites cytoplasmiques. Dans l'étude de cytophotométrie à balayage, la chromatine a été considérée à travers son constituant majeur, l'ADN, coloré par la réaction de Feulgen. Au cours de la régénération du membre, l'hétérochromatine initialement condensée, essentiellement accolée à la membrane nucléaire se décondense. Les vacuoles du cytoplasme, caractéristiques des animaux âgés par rapport aux animaux jeunes, disparaissent, les mitochondries et le reticulum endoplasmique rugueux deviennent plus abondants. Les caractéristiques nucléaires de l'activation cellulaire apparaissent précocement, précédent les modifications cytoplasmiques et conduisent à des cellules en tous points identiques aux cellules d'animaux jeunes en dehors de tout processus régénératif. Cette phase d'euchromatisation et de restructuration cytoplasmique est peut-être nécessaire à l'accroissement d'activité métabolique et à la division cellulaire qui suivent. Son déroulement peut expliquer tout au moins le ralentissement de la régénération observé chez les animaux âgés par rapport aux animaux jeunes.
    Notes: Summary Cartilaginous cells of aged newts (Triturus cristatus) were studied during hind limb regeneration. The electron microscope was used to study the structure and distribution of chromatin in the cell nuclei, while the DNA content of the chromatin was measured by means of a scanning cytophotometer. Changes in the ultrastructure of the cytoplasm during regeneration were also studied. It was observed that the structure and distribution of chromatin in the activated cell is greatly modified. In the non-activated cell of the aged newt, the chromatin is found highly condensed and distributed peripherally close to the nuclear membrane. In contrast, in the activated cells, the chromatin is much less condensed and is distributed throughout the nucleus. Moreover, cytoplasmic vacuoles, found only in the non-activated aged cells, disappear and an increase in the mitochondria and rough endoplasmic reticulum is also observed. Changes in the nuclear structure are observed prior to the cytoplasmic modifications. It is interesting to note that the process of activation induces structural changes in the aged cells which make these cells appear to be structurally identical to the young cells. This process of rejuvenation takes 3–5 days in the newt. We suggest that these structural changes of the chromatin and cytoplasm in the aged cells are necessary to increase the metabolic activity which precedes cell division. It may also explain why regeneration takes a longer time in the aged animals than in the young ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848254
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Nemaline myopathy: Histological, histochemical and ultrastructural studies (1978)
    Springer
    Acta neuropathologica 42 (1978), S. 33-41 
    Details
    ISSN: 1432-0533
    Keywords: Nemaline myopathy ; Neuromuscular junction ; Myotendinous junction-like structure ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Histological, histochemical and ultrastructural studies were performed on muscle biopsies from three siblings with congenital nemaline myopathy. Histological studies revealed type I fibre atrophy and type II fibre paucity. Ultrastructural studies of intramuscular nerves showed that the axonal diameters were very narrow compared with the width of myelin lamellae. Granular or membranous osmiophilic material occurred in the adaxonal Schwann cell cytoplasm and had a periodicity of 33–38Å. The neuromuscular junctions showed degenerative features such as glycogen granules or myelin figures in 27.1% of total terminal axons. The secondary synaptic clefts were markedly decreased in number and short in length. Myotendinous junction-like structures were found in 5.5% of the muscle fibres near the neuromuscular junctions, and often near sites of fibre-splitting. Rods in nemaline myopathy might be caused as a result of longitudinal splitting and disruption of fibres due to deficient regeneration of the muscle fibres associated with neurotrophic abnormalities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01273264
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Choroid plexus papilloma: Light and electron microscopic study of three cases (1978)
    Springer
    Acta neuropathologica 44 (1978), S. 235-239 
    Details
    ISSN: 1432-0533
    Keywords: Choroid plexus papilloma ; Ultrastructure ; Cytoplasmic ; Inclusions ; Silver bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three cases of choroid plexus papilloma were studied by light and electron microscopy. All had the typical papillary pattern, and, in addition, two exhibited solid areas of tumor growth which predominated in one case. PAS positive (diastase resistant) and argyrophilic cytoplasmic inclusions were present in all three tumors but were particularly abundant in the predominantly solid one. Ultrastructurally, the inclusions appeared as irregularly shaped structures containing lipid droplets, filamentous material and microtubules, and resembled the “silver bodies” of Biondi found in normal choroid plexus. Along with other ultrastructural features of normal choroid plexus, these cytoplasmic inclusions may be helpful in the differential diagnosis of papillary tumors involving the ventricular system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691073
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Ultrastructure of oncocytic adenoma of the human pituitary gland (1978)
    Springer
    Acta neuropathologica 41 (1978), S. 169-171 
    Details
    ISSN: 1432-0533
    Keywords: Pituitary gland ; Oncocytic adenoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cases of oncocytic adenoma occurring in the pituitary are reported. Both were men aged 40 and 50 years respectively and there was no evidence of endocrine abnormality. In both the tumours many cells showed abundant acidophilic finely granular cytoplasm which had not stained positively with PAS-orange G stain. Electron microscopically the cells contained numerous mitochondria associated with marked reduction of other cytoplasmic organelles including the secretory granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00689770
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Myélinopathie par intoxication oxycarbonée. Neuropathologie ultrasturale (1978)
    Springer
    Acta neuropathologica 43 (1978), S. 153-159 
    Details
    ISSN: 1432-0533
    Keywords: Myelin ; Oligodendroglia ; Human pathology ; Ultrastructure ; Carbon monoxyde ; Anoxia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 24-year-old woman was found comatose after 2 days of cephalalgia and vomiting. An immediate diagnosis of carbon monoxyde poisoning was disclaimed when blood carbon monoxyde was found to be 1.75 ml/100. A diagnosis of acute intracranial hypertension led to trephination with ventricular punction and brain biopsy on the third day. The patient died on the eleventh day. Ultrastructural study of biopsy tissue showed nearly normal cortex, and injured white matter, with disrupted or destroyed myelin and pycnotic oligodendroglia in contrast with nearly normal axons, astrocytes, and capillaries. Autopsy showed a typical semioval center myelinopathy. After discussion of the histotoxic, vascular, and edema theories for myelinopathy pathogenesis, primary oligodendrogial lesion is considered, and correlated with the diphasic evolution often observed in the course of carbon monoxyde myelinopathy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685010
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Morphological, biochemical, ultrastructural, tissue culture and clinical observations of typical and aggressive craniopharyngiomas (1978)
    Springer
    Acta neuropathologica 43 (1978), S. 191-203 
    Details
    ISSN: 1432-0533
    Keywords: Cultured ; Craniopharyngioma ; Typical ; Atypical ; Ultrastructure ; Electron microscopy ; Biochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Craniopharyngiomas are tumors of the suprasellar area, which are often cystic, encapsulated and slow-growing. Certain of these tumors can behave in an aggressive manner and either invade surrounding structures or recur. In order to determine characteristics which may aid in distinguishing typical from atypical lesions, a study of biopsy and tissue culture specimens from 25 human craniopharyngiomas was undertaken. Tissue culture observations reveal two distinct cell populations. Typical lesions grew in culture in an orderly epithelial pattern and had desmosome-tonofibril aggregates and smooth surface topography demonstrable by electron microscopy. In the atypical tumors the cell growth was irregular, with mitotic activity, cholesterol crystals and features characteristic of neoplastic transformation, such as surface microvilli, an increase of cytoplasmic basophilia, size and number of nucleoli and retraction of cytoplasm. Correlation with the clinical status of the patients suggests that tumors of the four patients which exhibited atypical features in culture behaved more aggressively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691578
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Primary cerebral neuroblastoma: A light and electron microscopic study (1978)
    Springer
    Acta neuropathologica 41 (1978), S. 119-124 
    Details
    ISSN: 1432-0533
    Keywords: Neuroblastoma ; Small-cell neoplasm ; Cerebral ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A small-cell neoplasm in the left temporal lobe of a 10 and a half year old boy was studied by light and electron microscopy. Routine sections of the mass showed a differentiating neuroblastoma with Homer Wright rosettes, several foci of immature neoplastic neurons (ganglion cells), many mitoses, arcas of necrosis and tumor vessels showing endothelial proliferation. Ultrastructurally, most cells resembled early fetal neuroblasts and also were similar to those in murine and peripheral human neuroblastomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00689762
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Dysplastic gangliocytoma of the cerebellum—An ultrastructural study (1978)
    Springer
    Acta neuropathologica 42 (1978), S. 1-5 
    Details
    ISSN: 1432-0533
    Keywords: Dysplastic gangliocytoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of dysplastic gangliocytoma of the cerebellum, a rare disorder with unknown etiology and pathogenesis, was studied ultrastructurally. The intranuclear inclusions identified were not seen to be of viral origin. The ultrastructural characteristics of the abnormal cells support the prevailing theory that these cells represent hypertrophied granular neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01273258
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    The spreading of focal brain edema induced by ultraviolet irradiation (1978)
    Springer
    Acta neuropathologica 42 (1978), S. 223-229 
    Details
    ISSN: 1432-0533
    Keywords: Irradiation edema ; Gravimetry ; Ultrastructure ; Vesicular transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Focal brain edema limited to one cerebral hemisphere was produced by ultraviolet irradiation of the exposed cortex. Tissue water content was determined by the gravimetric method which allows microsampling. Therefore, the spread of edema around the small necrotic area could be mapped more precisely than by determination of dry weight which calls for larger samples. As early as 30 min following irradiation, hyperemia and swelling of the brain are observed under the operating microscope. This correlates with venous stasis, hyperemia, and broadened perivascular spaces around venules and large capillaries accompanied by a marked rise in the specific weight of the tissue. After 4 h an edema front can be observed spreading from the perinecrotic zone in which there is a marked rise in endothelial cell vesicular activity. Edema reaches maximum levels in the deep white matter at 48 h post irradiation with normalisation of the tissue water content after 96 h. The velocity at which the edema front spreads from the cortex to the periventricular area lies in the range of 0.25 mm/h. Edema reabsorption coincides with signs of retrograde micropinocytosis in endothelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690361
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    The effects of cytochalasin B and colchicine on cell motility and ultrastructure in primary cultures of malignant gliomas (1978)
    Springer
    Acta neuropathologica 44 (1978), S. 21-30 
    Details
    ISSN: 1432-0533
    Keywords: Tissue cultures ; Cytochalasin B and colchicine ; Cell motility ; Ultrastructure ; Glioma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Primary tissue cultures of human gliomas were treated with cytochalasin B (0.5–60 μg/ml for 90 min). Cell motility was inhibited irreversibly in glial tumour cells, but the effect was reversible on the mesenchymal cells growing in culture in the lower dose range. Cell adhesion was considerably reduced as the dose was increased, as was the capacity for cells to spread on a surface from suspension. Low concentrations of cytochalasin B caused negligible cell death and little disruption of cell ultrastructure. However, increases in dose were accompanied by a greater predominance of rough endoplasmic reticulum and inclusions and aggregation of microfilament bundles. As seen by scanning electron microscopy, cytochalasin B caused the withdrawal of peripheral cell borders, disappearance of ruffles and the breakdown of cytoplasmic lamellae. Charateristic surface blebs and folds appeared in their place. By comparison, colchicine (1–10 μg/ml) caused a less marked and non-specific reversible reduction in cell motility on both glial and mesenchymal cells. No significant change in cell adhesion or spreading took place even at high doses, although at all concentrations gross disruption of the cell surface took place with changes in ultrastructure characterised by loss of cytoplasmic microtubules and aggregation of 10 nm filaments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691635
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Retention of the differentiated state by larvalXenopus liver cells in primary culture (1978)
    Springer
    Development genes and evolution 185 (1978), S. 235-248 
    Details
    ISSN: 1432-041X
    Keywords: Liver ; Primary culture ; Ultrastructure ; Albumin synthesis ; Xenopus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscopic analysis of primary cultures derived from larvalXenopus liver has shown that these cells, although they form only two-dimensional aggregates, retain and presumably also develop structural characteristics typical of liver parenchyma cells, such as bile canaliculi with microvilli and epithelial junctional complexes. As judged from structural criteria, primary cultures contain 80–90% hepatocytes. In contrast to the intact tissue, primary cultures showed excessive development of microfilaments, however. Incorporation of labeled amino acids has revealed further that the capacity for protein synthesis is maintained in culture and that synthesis of liverspecific protein albumin is maintained in vitro, even in liver cultures derived from thyrostatic tadpoles. This latter result suggests that initiation of albumin synthesis in the larval liver is probably not dependent upon thyroid hormones but rather reflects the protodifferentiated state of this tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848354
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Ultrastructure, histology, and innervation of the mantle edge of the freshwater pulmonate snailsLymnaea stagnalis andBiomphalaria pfeifferi (1978)
    Springer
    Calcified tissue international 26 (1978), S. 271-282 
    Details
    ISSN: 1432-0827
    Keywords: Shell formation ; Free nerve endings ; Ultrastructure ; Lymnaea stagnalis ; Biomphalaria pfeifferi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The mantle edge of the freshwater pulmonate snailsLymnaea stagnalis andBiomphalaria pfeifferi was investigated with histochemical and ultrastructural methods. The mantle edge gland, which is involved in shell formation, consists of the periostracal groove and the belt. This belt appears to be composed of various regions. In the area of the periostracal groove a number of subepithelial gland cell types occur; these release their products into the groove. Between the groove cells ciliated free nerve endings terminate; the corresponding perikarya occur in the subepidermal connective tissue. Also in the posterior belt region free nerve endings were observed between the epithelial cells; in addition, a particular type of subepithelial gland cell was found in this area. The epithelial cells of this part of the belt have the ultrastructural characteristics of ion and water transporting cells; they are probably involved in calcium deposition and resorption. The possible role of the free nerve endings and of the subepithelial gland cells is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013270
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Whole-body retention of mercury and selenium and histopathological and morphological studies of kidneys and liver of rats exposed repeatedly to mercuric chloride and sodium selenite (1978)
    Springer
    Archives of toxicology 40 (1978), S. 189-199 
    Details
    ISSN: 1432-0738
    Keywords: Mercury ; Selenium ; Retention ; Liver ; Kidney ; Ultrastructure ; Interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Distribution and retention of mercury and selenium was studied in rats exposed repeatedly to HgCl2 injections (0.5 mg Hg/kg to the tail vein every other day) and intragastrically to Na2SeO3 (0.5 mg Se/kg every day), applying combined and separate administration of these metals for 2 weeks. Whole-body retention of mercury in the presence of selenium was augmented by 20% and that of selenium in the presence of mercury by 4% with respect to the administered dose. Combined administration of mercuric chloride and sodium selenite brought about damage to the epithelial cells of renal proximal convolutions and formation of protein casts in their lumen. These changes had the same pattern as those induced by administration of mercuric chloride alone, but the intensity was lower. Submicroscopic studies revealed that repeated combined administration of sodium selenite and mercuric chloride did not completely abolish the mercury-induced mitochondrial swelling and contributed to chromatin destruction in the hepatocyte nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00364650
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Über das Vorkommen sog. heller Zellen in Speicheldrüsentumoren (1978)
    Springer
    Journal of cancer research and clinical oncology 91 (1978), S. 165-182 
    Details
    ISSN: 1432-1335
    Keywords: Clear cells ; Salivary gland tumors ; Ultrastructure ; Differential diagnosis ; Helle Zellen ; Speicheldrüsentumoren ; Ultrastruktur ; Differentialdiagnose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zu den hellzelligen Speicheldrüsentumoren gehören monomorphe hellzellige Adenome, hellzellige Carcinome, hellzellige Varianten der Acinus- und Mucoepidermoidtumoren, Talgdrüsentumoren, Speichelgang-Carcinome und pleomorphe Adenome mit hellzelligen Abschnitten. Der lichtmikroskopische, deskriptive Begriff der hellen Zelle umfaßt bei einer weiteren cytochemischen und elektronenmikroskopischen Analyse Zellformen unterschiedlicher Herkunft und funktioneller Bedeutung. Folgende Zelltypen wurden näher analysiert: indifferente Gangzellen (geringe Organellenausbildung, Desmosomen), speichernde Streifenstückzellen (Glykogengranula, zahlreiche Mitochondrien, basales Labyrinth), Myoepithelzellen (Myofilamente, Pinocytose-Vesicel, Lipofuscingranula, Hemidesmosomen), epidermoide Zellen (Tonofilamente, Desmosomen), Becherzellen (Schleimvacuolen, basales endoplasmatisches Reticulum), Talgdrüsenzellen (Lipidtropfen, Mikrovilli, Desmosomen) und helle Acinuszellen (elektronenoptisch helle Sekretgranula, kleine Mitochondrien, kleiner Golgiapparat). In die Differentialdiagnose müssen auch hellzellige Tumorformen der Speicheldrüsenregion einbezogen werden, welche primär nicht vom Speicheldrüsengewebe ausgehen. Hierzu gehören Metastasen hypernephroider Nieren-Carcinome, Paragangliome, Glomustumoren Masson, Granularzelltumoren und alveoläre Weichteilsarkome.
    Notes: Summary Clear cell tumors of the salivary glands are monomorphic clear cell adenomas, clear cell carcinomas, clear cell variants of acinic cell and mucoepidermoid tumours, sebaceous cell tumors, salivary duct carcinomas and pleomorphic adenomas with clear cell sectors. At the light microscopical level the descriptive term of the clear cell comprises cell types of different origin and functional importance which can be differentiated by cytochemistry and electron microscopy. The following cell types were analysed precisely: indifferent duct cells (small formation of organelles, desmosomes), storing striated duct cells (glycogen granules, multiple mitochondrias, basal labyrinth), myoepithelial cells (myofilaments, pinocytosis vesicles, lipofuscin granules, hemidesmosomes), goblet cells (mucous vacuoles, basal endoplasmatic reticulum), sebaceous cells (lipid droplets, microvilli, desmosomes) and clear acinic cells (electron pale secretory granules, small mitochondrias, small golgi apparatus). Clear cell tumor types of the salivary gland region which primarely do not derive from the salivary gland tissue must also be included in the differential diagnoses. These are metastases of hypernephroid renal carcinomas, paragangliomas, glomus tumors of Masson, granular cell tumor and alveolar soft-part sarcomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00284023
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Ultrastructural studies on hydantoin induced lymphomas in mice (1978)
    Springer
    Journal of cancer research and clinical oncology 91 (1978), S. 195-204 
    Details
    ISSN: 1432-1335
    Keywords: Hydantoin ; Malignant Lymphoma ; Mice ; Ultrastructure ; Hydantoin ; Maligne Lymphome ; Maus ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ultrastrukturelle Zellveränderungen werden beschrieben am Original-Tumorgewebe und an Tumorzellen aus der Kurzzeitkultur von malignen Lymphomen, induziert durch chronische Diphenylhydantoin-Exposition. Diese Tumoren entstanden in Mäuse-Inzuchtlinien mit niedriger (C57Bl) und hoher (SJL/J) spontaner Lymphomrate im fortgeschrittenen Alter, waren jedoch nicht induzierbar in einer Lymphom-resistenten Linie (C3Hf). Frühveränderungen des lymphoretikulären Gewebes bestanden in einer zunehmenden Atrophie des Thymus und der thymusabhängigen Partien, begleitet von einer diffusen retikulo-histiozytären Hyperplasie. Lymphome vom lymphoblastischen Typ entstanden im Thymus nach einer Latenzzeit von 4–8 Monaten mit nachfolgender Generalisation. Verschiedene atypische Veränderungen wurden an Tumorzellen beobachtet sowie das Auftreten von C-Typ-Partikeln in den Tumorzellkulturen und hinsichtlich der Pathogenese der Lymphome diskutiert.
    Notes: Summary Ultrastructural studies were done on cells from original tumors and from short time cultures of mouse thymic lymphomas experimentally induced by chronic exposure to diphenyl-hydantoin. The tumors appeared in mouse strains with low (C57Bl) and high (SJL/J) susceptibility to spontaneous lymphoma development and were not observed in a resistant strain (C3Hf). Thymic lymphoma development was usually preceded by increasing lymphoreticular atrophy followed by progressive reticulohistiocytic hyperplasia, and subsequently spread to other tissues. Morphologically the tumor was characterized as a lymphoblastic lymphoma. Abnormal cell changes in the original tumors and cultured cells, and the presence of murine C-type particles in the cultured cells but not in the original tumors, are discused in relation with the disturbance of immune system and the lymphoma enhancement produced by diphenyl-hydantoin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00284026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Disappearence of the intracytoplasmic membranes inRhodopseudomonas sphaeroides (1978)
    Springer
    Archives of microbiology 117 (1978), S. 293-295 
    Details
    ISSN: 1432-072X
    Keywords: Rhodopseudomonas sphaeroides ; Intracytoplasmic membranes ; Membranes ; Ultrastructure ; Bacteriochlorophyll ; Chromatophores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The photosynthetic bacterium,Rhodopseudomonas sphaeroides, can be grown phototrophically (light, anaerobiosis), of chemotrophically (dark, aerobiosis). In the first case, it contains intracytoplasmic membranes with photosynthetic pigments. When shifted from phototrophy to chemotrophy these membranes disappear in an unknown fashion. In the present experiment, samples were taken for electron microscopy, cell density and bacteriochlorophyll determinations after shift from phototrophy to chemotrophy. The density of intracytoplasmic vesicles was measured on micrographs. During the first 2h growth is very slow and the ultrastructure remains unaltered. As growth resumes, the vesicles disappear at a rate which implies that they are not incorportated into the cytoplasmic membrane, nor actively digested, but remain intact and become increasingly diluted in the cytoplasm as the culture grows. The size of the vesicles was estimated to about 500 Å. The number of vesicles in phototrophically grown cells was calculated to about 575 per cell, and after 6h chemotrophic growth to about 100. The areas of the cytoplasmic and intracytoplasmic membranes are roughly calculated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00738549
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Sporogenesis in Streptomyces melanochromogenes (1978)
    Springer
    Archives of microbiology 118 (1978), S. 309-316 
    Details
    ISSN: 1432-072X
    Keywords: Streptomyces melanochromogenes ; Sporogenesis ; Formation of sporulation septum ; Delimitation, separation, and release of spores ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mode of spore differentiation in a strain of Streptomyces melanochromogenes was followed by analysis of ultrathin sections of sporulating aerial hyphae at various stages of sporogenesis. A special accent was laid on the formation of the sporulation septum and its alterations in the course of spore delimitation and separation. Distinct differences in formation and substructure have been observed between the cross walls of vegetative hyphae and the sporulation septa. Cross walls of vegetative hyphae are formed in a way typical for Gram-positive bacteria by a centripetal annular ingrowth of cytoplasmic membrane, on which wall material immediately is deposited. The development of the sporulation septa is characterized by the accumulation of amorphous material in addition to the newly synthesized wall layer inside the invaginating cytoplasmic membrane. This amorphous septal material will later be decomposed presumably by two lytic systems which cause the separation of the spores. The central region of the finished sporulation septum is perforated by microplasmodesmata. Spores are released by a break down of the surface sheath. The complete spores are enveloped by a twolayered cell wall and the spiny surface sheath.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00429123
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Ultrastructural study of microcyclic macroconidiation in Neurospora crassa (1978)
    Springer
    Archives of microbiology 116 (1978), S. 279-288 
    Details
    ISSN: 1432-072X
    Keywords: Neurospora crassa ; Macroconidia ; Microcycle ; Heat ; Ultrastructure ; Nucleolus ; Proconidia ; Septa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Heat-shock of macroconidia of Neurospora crassa at 46°C followed by shift-down to 25°C determines premature conidiogenesis. The nuclei and cytoplasm of heat-treated, swollen conidia contain spots of a dense material especially concentrated around the nucleolus in short time treated ones. In the first proconidium apically budding on the enlarged tip of the premature conidiophore, small vesicles are peripherally spread. A few such vesicles are later seen lining the initially simple septum separating the proconidial units into conidia. The doubling of this interconidial septum is surface viewn as a thick annulus. Disarticulation of the conidial units intervenes along a septal furrow of electroluscent material. Interconidial continuity through the septal pores is transiently insured by a connective which is ruptured for final liberation of the conidia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00417852
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Kleinhirnastrocytome und Opticusgliome — eine vergleichende feinstrukturelle Untersuchung (1978)
    Springer
    Virchows Archiv 380 (1978), S. 59-79 
    Details
    ISSN: 1432-2307
    Keywords: Cerebellar astrocytoma ; Optic glioma ; Pilocytic astrocytoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural comparison of 8 cerebellar astrocytomas and 4 optic gliomas shows that the morphological patterns of both tumor-groups are identical. The confusion in nomenclature of these tumors is discussed and reasons for a preference for the term “pilocytic astrocytomas” are given. Further, pilocytic astrocytes seem to be a special, phylogenetically older, group of glial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432893
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Immunhistochemical and electron microscope analysis of adenomas of the thyroid gland (1978)
    Springer
    Virchows Archiv 380 (1978), S. 205-220 
    Details
    ISSN: 1432-2307
    Keywords: Thyroid ; Adenoma ; Ultrastructure ; Immunhistochemistry ; Thyroglobulin ; Lysosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Histological, immunhistochemical and electronmicroscopic studies of 12 human, scintigraphically “cold”, thyroid adenomas with specific cytological differentiation identified four different cell types: oxiphil cell, clear cell, ergastoplasm-rich cell and mitochondrion-rich cell. The oxiphil tumor cell can be recognized light-microscopically by its large size and its eosinophilic granular cytoplasm. Most of these cells do not produce thyroglobulin. The ultrastructural characteristics of oxyphil cells are principally mitochondria in great numbers and many large lysosomes. Clear cell adenomas show a trabecular growth pattern. The tumor cells have an abundance of cytoplasm which contains small acidophilic granules. Immunhistochemically we were able to demonstrate thyroglobulin in small amounts within cytoplasmic granules and more extensively within the follicle lumina. Electronmicroscopically we observed a large number of smooth surfaced vacuoles of varying size, extraordinary large lysosomes and occasional cisternae of rough endoplasmic reticulum, the latter probably corresponding to the immune-histochemically identified thyroglobulin granules. The ergastoplasm-rich-cell adenomas, which to the best of our knowledge have not been previously described, show a predominantly micro-to normofollicular architecture histologically without intrafollicular colloid. The cytoplasm of the ergastoplasm-rich cells reveales a strong positive thyroglobulin-staining reaction. The fine structure of these cells is characterized by the abundance of cisternae of the rough endoplasmic reticulum. The mitochondrion-rich-cell adenomas exhibited a microfollicular structure with an intensive acidophilic granular staining at the basal part of the tumor cells. Immunhistochemically and electronmicroscopically we found some morphologic and functional features which differentiate these cells from the oxyphil cell. Thyroglobulin was located predominantly in the apical portion of the cytoplasm in the mitochondrion-rich cells without sharp demarcation from the luminar thyroglobulin. Electron microscopically fewer basal and laterally located mitochondria were seen in mitochondrion-rich cells compared with oxyphil cells. As we could not find any sign of functional activity in the oxyphilic, clear cell and ergastoplasm-rich cell adenomas we analysed those aspects of the lysosomal system not concerned with the enzymatic digestion of thyroglobulin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00430459
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    A freeze-fracture study of tight junctions in the pars convoluta and pars recta of the renal proximal tubule (1978)
    Springer
    Cell & tissue research 186 (1978), S. 121-133 
    Details
    ISSN: 1432-0878
    Keywords: Proximal tubule ; Tight junctions ; Ultrastructure ; Electron microscopy ; Freeze fracturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology of tight junctions of the renal proximal tubule was studied comparing the pars convoluta and pars recta of rat, golden hamster, rabbit, cat, dog and tupaia. Though some interspecies variations were observed, the convoluted portions of the proximal tubules revealed quite uniformly very leaky tight junctions with mainly 1–2 strands. Along the whole proximal tubule of the rabbit kidney including the pars recta only minor differences of the zonulae occludentes were found. By contrast, the tight junctions of the pars recta in other species were much more elaborate, especially in cat and tupaia, having up to 6 strands and an overall depth of more than 150 nm. The implications of these findings are discussed with special regard to the functional differences between the pars convoluta and pars recta of the proximal tubule.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219659
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Exocrine pancreas under experimental conditions (1978)
    Springer
    Cell & tissue research 186 (1978), S. 227-240 
    Details
    ISSN: 1432-0878
    Keywords: Pancreas (rat) ; Pancreatic duct ligation ; Cell membrane ; Intercellular junctions ; Ultrastructure ; Freeze fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Exocrine pancreatic tissue was investigated during various intervals after pancreatic duct ligation. Concomitant to the increase of the intraluminal pressure, alterations are found in the arrangement of the luminal membrane surface and the zonulae occludentes of the acinar cells. The zonulae occludentes exhibit a disarrangement of their strands. The number of strands diminishes and small interruptions as well as large discontinuities of the strands are observed in most regions of the acinar cells. Furthermore, gap junctions are found very infrequently between acinar cells. The ultrastructural alterations of the zonulae occludentes suggest a gradual adaptation to the increasing unilateral pressure. However, a leakage of the paracellular permeability barrier occurs which contributes to the known shunt between the compartments of the pancreatic juice and the interstitial space following pancreatic duct obstruction. The present investigation is a further example of alterations in the paracellular permeability and intercellular communication of epithelial cells under pathological conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225533
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Fine structure of the eyes of orb-weavers, Argiope amoena L. Koch (Aranea: Argiopidae) (1978)
    Springer
    Cell & tissue research 186 (1978), S. 435-452 
    Details
    ISSN: 1432-0878
    Keywords: Photoreceptors ; Arthropod ; Spider (Argiope amoena) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The anterolateral eye, the posterolateral eye and the posteromedial eye of the web-building spider, Argiope amoena have been examined by light and electron microscopy. The dioptric apparatus of all three eyes is similar in structure, and consists of a cornea, a lens and a vitreous body. The retina contains monopolar receptor cells, the cell bodies of which are present beneath the vitreous body in all three eyes. Proximal processes of the receptor cells form rhabdoms beneath the cell body layer and then extend toward the first optic glomerulus as an ocellar nerve. Two distinct patterns of retinal organization are present in the three eyes. In one type the rhabdomic layer of the retina is backed by a pigmented layer. In the other type the rhabdomic layer is backed by a tapetal reflecting layer. Rhabdomic structure and cytoplasmic inclusions of the receptor cells differ greatly between the two types. The anterolateral eye possesses a single type of retina with the rhabdoms backed by the tapetum. Both the posterolateral and the posteromedial eye are similar in structure, each possessing beneath the common dioptric apparatus retinae of both types.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224933
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Ultrastructure of the subfornical organ of the Japanese quail, Coturnix coturnix (1978)
    Springer
    Cell & tissue research 188 (1978), S. 19-33 
    Details
    ISSN: 1432-0878
    Keywords: Subfornical organ ; Circumventricular organ ; Coturnix quail ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of the subfornical organ (SFO) of the Japanese quail has been studied by light and electron microscopy. The SFO is a small semiglobular bulge in the midline on the rostrodorsal wall of the third ventricle between the anterior commissure and tela choroidea. The organ consists of three main parts, anterior stalk, the corpus and the posterior stalk. The anterior stalk is covered by ependymal cells with a few cilia, but the corpus and posterior stalk are characterized by a distinctive lack of cilia and by flat or bulging cell surfaces, which have the appearance of cobble stones. The large bulbous protrusions in the ependymal surface of the posterior stalk suggest a secretory function into the ventricle. In the subependymal layer, there are a few parvocellular neurons that contain small mitochondria, moderately developed Golgi apparatus, lysosomes, dilated cisternae of rER and a few dense-cored granules of 100–120 nm in diameter. They appear to be secretory in nature. Two types of glial cells occur in the subependymal and internal layers. One is small and spindle-shaped with a dense nucleus and elongated cytoplasmic processes; it may be microglial. The other is a small polygonal cell with rounded nucleus and clear cytoplasm containing bundles of filaments; it may be a protoplasmic astrocyte. The neuropil contains three types of axons. The first contains dense-cored granules, 80 nm in diameter, and clear vesicles, 40–60 nm in diameter and is involved in axosomatic synapses. The second type contains dense granules, 120 nm in diameter, and clear vesicles, 40–80 nm in diameter, and shows axodendritic synapses. The third contains peptidergic granules about 100–120 nm in diameter and seems to belong to the organ-specific nerve cells. These axons terminate at the perivascular space of the blood capillaries, suggesting secretion into the blood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220512
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Origin of the glial processes responsible for the spontaneous postnatal phagocytosis of boutons on cat spinal motoneurons (1978)
    Springer
    Cell & tissue research 189 (1978), S. 203-217 
    Details
    ISSN: 1432-0878
    Keywords: Astrocytes ; Development ; Phagocytosis ; Neuroplasticity ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previous studies have demonstrated that astrocyte processes are responsible for a spontaneously occurring phagocytosis of boutons on cat spinal motoneurons during the second postnatal week. In the present investigation, the astrocytes and the astrocyte processes in contact with the motoneurons were studied qualitatively and quantitatively during the early postnatal period. It could be concluded that the cells responsible for the phagocytosis of boutons are immature astrocytes. These cells were present not only during the period of phagocytosis but also prior to this period. The type of process responsible for the phagocytosis was present not only during the period of phagocytosis but also prior to and after that period although the relative contribution of such processes to the glia-covered membrane area of the motoneurons was reduced in the older animals. On the basis of these results, the possible specificity of the immature astrocyte as the element responsible for the phagocytosis of boutons during normal development is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209270
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Synaptic junctions in the sinus gland of the freshwater prawn Palaemon paucidens (1978)
    Springer
    Cell & tissue research 189 (1978), S. 435-440 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Sinus gland ; Synapses ; Palaemon ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of neurosecretory fibers, designated as Type 5 and Type 6 axons, in the sinus gland of the freshwater prawn, Palaemon, establish contact with other neurosecretory axons by means of synaptic junctions. This finding strongly supports the view that release of some neurohormones from the eyestalk may be regulated by neurosecretory neurons through synaptic transmission.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209131
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Structure of occluding junctions in ileal epithelial cells of suckling rats (1978)
    Springer
    Cell & tissue research 191 (1978), S. 449-462 
    Details
    ISSN: 1432-0878
    Keywords: Ileum (Rat) ; Occluding junctions ; Freeze-fracture ; Ultrastructure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two kinds of occluding junctions are found between ileal epithelial cells of suckling rats: apical zonulae occludentes (ZO) and fasciae occludentes (FO) which are associated with the lateral plasma membranes of many epithelial cells. In unfixed preparations, glycerol treatment induces the further proliferation of extensive fasciae occludentes. Both kinds of junction have identical structural elements when visualized in freeze fracture replicas, although the arrangement of these elements differs. Zonulae occludentes consist of networks of branching and anastomosing linear ridges or rows of ∼10 nm particles with 20–30 nm spaces between the rows which form narrow belt-like structures around the apical region of adjacent cells. Fasciae occludentes, on the other hand, consist of similar linear ridges or rows of particles but the junction strands are often discontinuous, open ended and only occasionally intersect with each other. Several different fracture planes through the plasma membrane in the region of the occluding junctions have been observed and these provide further evidence that two components, one from each membrane, fused at the level of the extracellular space, form the junction sealing element. Furthermore, we present evidence which indicates a staggered rather than an in-register arrangement of these two components.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219808
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Effects of hormone-releasing stimuli on the area of the perivascular space in the neural lobe of the rat (1978)
    Springer
    Cell & tissue research 191 (1978), S. 501-506 
    Details
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Ultrastructure ; Perivascular space ; Hormonerelease ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes from rats subjected to neurohypophysial hormone-releasing stimuli were examined electron microscopically following fixation in 4 % tannic acid in 2.5 % glutaraldehyde. This fixation allowed the delineation of the perivascular space in the neural lobe tissue. Measurement of the area of the perivascular space showed that it was significantly increased in the rats subjected to vagal stimulation and intraarterial calcium ions compared to the control rats. The rats which had been subjected to haemorrhage as a hormonereleasing stimulus did not show any significant change in the area of the perivascular space. The significance of these findings in relation to hormone release is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219812
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Lymph node macrophages and reticulum cells in the immune response (1978)
    Springer
    Cell & tissue research 192 (1978), S. 1-23 
    Details
    ISSN: 1432-0878
    Keywords: Lymph node (rat) ; Macrophages ; Dendritic reticulum cells ; Immune response to paratyphoid vaccine ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The reactivity of rat lymph node macrophages and reticulum cells has been studied in relation to the course of the immune response. Special attention was paid to the interdigitating cells (IDC) in the paracortex and the dendritic reticulum cells (DRC) in the germinal centre. Different types of macrophage predominate in the three different phases of the immune response. In the induction phase exudate macrophages predominate. They transform their morphology depending on the micro-environment in which they settle. These cells may contain Birbeck granules. Our experiments suggest, that these granules are immunologically specific organelles, associated with the induction of a primary humoral response. In the proliferation phase transitional cells between newly arrived macrophages and IDC predominate in the paracortex and the number of IDC decreases. In the memory phase IDC repopulate this thymus dependent area, indicating that the characteristic morphology of these cells results from the immune response in the T cell environment. The DRC are specifically related to the germinal centre, the morphological transformation of this peculiar reticulum cell occurs under the influence of the germinal centre reaction. The germinal centre reaction originates by tingible body macrophages (TBM).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231019
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Morphological changes in the esophageal epithelium of the eel, Anguilla japonica, during adaptation to seawater (1978)
    Springer
    Cell & tissue research 192 (1978), S. 25-38 
    Details
    ISSN: 1432-0878
    Keywords: Esophageal epithelium ; Eel ; Seawater adaptation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The esophageal epithelium of the Japanese eel, Anguilla japonica, was studied by light and electron microscopy. In freshwater-adapted eels, longitudinal folds of the mucosal surface are simple in form and lined by a stratified epithelium composed of mucous cells, filament and ribosome-rich cells. Mucous cells are numerous. The filament-rich cells form the outermost and the basal layers of the stratified epithelium and are scattered in the middle zone among the mucous cells. They are firmly bound to one another by many desmosomes and prominent interdigitations of plasma membrane. The distal free surface of the filament-rich cell has a fingerprint-like pattern of microridges. A small number of columnar cells occur at the apices of the folds. They are rich in mitochondria and their distal surfaces bear short microvilli. In seawater-adapted eels, irregularly meandering folds increase the surface area of the mucosa. The stratified epithelium is extensively replaced by a simple columnar epithelium free of mucous cells. The columnar cells resemble in many respects those found in freshwater-adapted eels. They are rich in mitochondria and their distal free surface were provided with short microvilli. However, prominent lateral intercellular spaces and elaborate interdigitations of cytoplasmic processes in the distal zone distinguish the former from the latter. Results are considered in connection with the changes in ion and water permeability of the epithelium after seawater adaptation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231020
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Ultrastructure of capillaries in the conduction system of the heart in various mammals (1978)
    Springer
    Cell & tissue research 192 (1978), S. 77-87 
    Details
    ISSN: 1432-0878
    Keywords: AV-node ; AV-bundle ; Fenestrated capillary endothelium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The capillaries in the atrioventricular node and atrioventricular bundle of the heart (mammals) were investigated by thin sections and freezeetch replicas. Fenestrated endothelial cells were found to occur in all mammals examined in this study. These fenestrations (500±50 Å diameter) are bridged by a diaphragm and occur in relatively small sieve areas. In contrast to the AV-node and AV-bundle, the non-specialized myocardium is supplied by continuous capillaries. The presence of the fenestrated capillary in the conduction system of the heart may serve to increase both permeability and passive transport capacity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231024
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    A stereological ultrastructural study of peritoneal macrophages from germ-free and conventionally-reared mice (1978)
    Springer
    Cell & tissue research 192 (1978), S. 157-166 
    Details
    ISSN: 1432-0878
    Keywords: Germ-free mice ; Macrophages ; Peritoneum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The reported work is the first direct ultrastructural comparison of resident peritoneal macrophages from germ-free and conventional animals. Three groups of mice were studied: germ-free (GF), conventionally-reared under isolation conditions (IC), and conventionally-reared in an open environment (OC). The macrophages from the three groups of animals are closely similar morphologically. Particularly noteworthy are the electron-dense, lysosome-like granules which are numerous in the macrophages of germfree mice and which provide a structural foundation for the presumed microbicidal capability of the phagocytes. Morphometric estimates showed that the “average macrophage” from GF mice is smaller and possesses a smaller, rounder nucleus, a smaller volume fraction of mitochondria and more lysosome-like granules per unit of cytoplasmic volume than the “average macrophage” from conventional mice. Moreover, granules and mitochondria are smaller, on average, in the GF phagocytes than in macrophages from conventional mice. The results suggest that peritoneal macrophages from the germ-free mouse represent, more truly than those from the conventional mouse, the nature of the fully differentiated but as yet unstimulated mononuclear phagocyte.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231030
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Ultrastructural analysis of the action of reserpine on the brain neuroendocrine system of the wax moth, Galleria mellonella L., Lepidoptera (1978)
    Springer
    Cell & tissue research 192 (1978), S. 143-155 
    Details
    ISSN: 1432-0878
    Keywords: Neuroendocrine system ; Galleria ; Ultrastructure ; Reserpine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This study concerns the influence of reserpine on the fine structure of peptidergic neurosecretory cells in the pars intercerebralis of Galleria mellonella, and of neurons containing smaller dense-cored vesicles (presumed to be aminergic) localized in the same area of the brain. The drug, administered in doses of 125 μm and 250 μg per g of insect body weight, reduces both the amount and the electron opacity of the dense-cored vesicles with a diameter of 60–80 nm in the neuronal perikarya as well as their terminals. Simultaneously, this treatment evokes an abnormal accumulation of secretory granules within the perikarya of peptidergic neurosecretory cells belonging to three types. This accumulation of secretory material is followed by some changes in the fine structure of these cells. One (fourth) type of neurosecretory cells seems to be insensitive to reserpine action. Participation of the aminergic system in the regulation of the secretory activity of some populations of peptidergic neurosecretory neurons of the insect brain is postulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231029
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Structure of the adenohypophysis in parturient female and neonate harp seals, Pagophilus groenlandicus (1978)
    Springer
    Cell & tissue research 192 (1978), S. 341-357 
    Details
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Cell types ; Neonate ; Parturient ; Harp seal, Phagophilus groenlandicus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pars distalis of parturient harp seals (Pagophilus groenlandicus) is divisible into three distinct zones based on the major cellular components of the different regions. A clear zonation is lacking in neonate seals, the medial “basophilic wedge” and the anterior gonadotrophic were small and difficult to identify. Five cell types were identified based on cytological characteristics: somatotrophs, mammotrophs, thyrotrophs, gonadotrophs and stellate cells; corticotrophs could not be identified, with any certainty, in any of the preparations, nor could the gonadotrophs be classified into LH, FSH, and ICSH cells. The pars intermedia enlarged during the early post-partum period and was large in the parturient females.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220751
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Studies on the ultrastructure and permeability of the hemotrichorial placenta (1978)
    Springer
    Cell & tissue research 192 (1978), S. 391-407 
    Details
    ISSN: 1432-0878
    Keywords: Placenta (rat) ; Permeability ; Tracer ; Intercellular junctions ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of lanthanum chloride and horseradish peroxidase within the full-term chorioallantoic placenta of the rat was investigated 1 to 20 min after administration of these tracers into the maternal blood circulation. Both tracers rapidly penetrate trophoblastic layer I and diffuse into the interspace between layers I and II. They are localized in extensive infoldings and caveolae of the outer surface of layer II. The syncytial character of layer II is confirmed at this developmental stage of the placenta. There is no vesicular uptake or penetration beyond layer II until 20 min after tracer administration. Our results indicate that trophoblastic layer II is the main barrier in the chorioallantoic rat placenta preventing the permeation of macromolecules from maternal to fetal compartments. With freeze-fracturing, particulate structures of variable arrangement and size are found between adjacent cells of layer I. With goniometric analysis small gaps between the appositions of the membrane are observed. These structures are interpreted as tight and/or gap junctions during stages of assembly or disassembly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212321
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Studies on the ultrastructure and permeability of the hemotrichorial placenta (1978)
    Springer
    Cell & tissue research 192 (1978), S. 409-422 
    Details
    ISSN: 1432-0878
    Keywords: Placenta (rat) ; Capillary ; Permeability ; Tracer ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of horseradish peroxidase and lanthanum chloride within the full term chorioallantoic placenta of the rat was examined after administration of these tracers into the umbilical artery. Both tracers rapidly traverse the capillary endothelium. Transendothelial channels, fenestrations and micropinocytotic vesicles provide the main pathways. Intercellular clefts which are either patent or interrupted by leaky intercellular junctions, also contribute to a rapid passage of low and high molecular weight substances. Deep channel-like invaginations, effecting an increase of the exchange area of layer III, are freely accessible to the tracers from the interspace between the capillary endothelium and trophoblastic layer III. The invaginations, however, are not in continuity with the interspace between layers II and III, verifying the syncytial character of layer III. Neither an uptake of the tracers nor a passage across layer III is observed. The main permeability barrier to feto-maternal transfer within the chorioallantoic placenta is localized in the syncytiotrophoblastic layer III. This layer controls the passage of low molecular weight substances and restricts the penetration of high molecular weight substances.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212322
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Control of the pars intermedia of the lizard, Anolis carolinensis (1978)
    Springer
    Cell & tissue research 186 (1978), S. 241-258 
    Details
    ISSN: 1432-0878
    Keywords: Neural lobe ; Anolis carolinensis ; Ultrastructure ; Intermediate lobe control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the neural lobe of the lizard, Anolis carolinensis, was studied after fixation in a threefold aldehyde solution. The neural lobe appeared as narrow vertical diverticula separated from one another and from the pars intermedia by a continuous vascular septum. No nerves passed through this septum. The ependymal, fibrous and external layers were readily recognized. Peptidergic fibres were the main component of the fibrous layer. The peptidergic endings were in intimate contact with the ependymal cells, suggesting that the ependyma mediates the release of neural lobe peptides. The external layer contained ependymal end-feet and numerous aminergic terminals, ending directly on the perivascular basal lamina and/or on the ependymal end-feet. The functional aspects are discussed in terms of intermediate lobe control. The findings suggest that aminergic substances take part in the control of the intermedia, but do not exclude the involvement of peptide hormones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225534
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Ultrastructure and lipid content of the liver of the zebrafish, Brachydanio rerio, related to vitellogenin synthesis (1978)
    Springer
    Cell & tissue research 186 (1978), S. 297-308 
    Details
    ISSN: 1432-0878
    Keywords: Liver ; Teleost ; Ultrastructure ; Lipid ; Vitellogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The female zebrafish is capable of producing mature eggs on the fifth day of each reproductive cycle. During this five-day period the ultrastructure of hepatocytes undergoes several changes. The number of nuclear pores increases rapidly during spawning, followed by a proliferation of RER within 24 h. Two days after spawning, glycogen has disappeared and the liver contains large amounts of lipids. The lipid droplets are closely surrounded by elongated mitochondria. Golgi complexes are abundant, secreting dense bodies. Four days after spawning the hepatocytes tend to regain their pre-spawning appearance. It is suggested that the changes in the hepatocytes, which coincide with special phases of ovarian activity, are related to vitellogenin synthesis. Steroids, especially estradiol-17β, may trigger this process in the liver.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225539
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    An ultrastructural study of the larval integument of the midge, Chironomus riparius meigen (Diptera: Chironomidae) (1978)
    Springer
    Cell & tissue research 186 (1978), S. 327-335 
    Details
    ISSN: 1432-0878
    Keywords: Cuticle ; Epidermis ; Chironomus ; Respiration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The larval integument of the midge, Chironomus riparius Mg., is unusually thin although it conforms with the normal insect pattern. The cuticle of the post-cephalic segments is about 3 μm thick and overlies an epidermis which has an irregular basal plasma membrane resulting in spaces occurring between it and the basement membrane. The ventral tubuli have a similar epidermis but the cuticle is somewhat thinner. The anal papillae have the thinnest cuticular covering with a uniquely folded epicuticle of variable thickness, and their epidermis has the characteristics of a transporting epithelium. No evidence of pore canals could be found in the cuticle of any part except the head capsule which has a remarkably smooth epicuticle and a distinct layer which may represent the exocuticle. There are no spaces between the basement membrane and basal plasma membrane of the epidermis in the head. Ultrastructural evidence would suggest that gaseous exchange can occur across most of the post-cephalic integument.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225541
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Effects of systemic administration of 6-hydroxydopamine on the circumventricular organs in nonhuman primates (1978)
    Springer
    Cell & tissue research 187 (1978), S. 115-127 
    Details
    ISSN: 1432-0878
    Keywords: Area postrema ; 6-Hydroxydopamine ; Degenerative changes ; Ultrastructure ; Cynomolgus and squirrel monkeys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 6-Hydroxydopamine (6-OH-DA) has been shown to produce degenerative changes in noradrenergic nerve terminals and preterminals in the CNS following intracisternal, intraventricular or direct injection into the brain parenchyma. Systemic injection of 6-OH-DA is known to result in degenerative changes in noradrenergic terminals in the peripheral nervous system. However, only a few studies have been carried out on the effects of systemic injections of 6 OH-DA on noradrenergic terminals in the CNS. In the present study cynomolgus and squirrel monkeys were injected intravenously on two successive days with total doses of 350mg/kg and 150 mg/kg of 6-OH-DA, respectively, and sacrificed at 2 and 24 h following the second injection. Degenerative changes in the area postrema (AP) neurons in all injected animals were characterized by a generalized increase in electron density of cytoplasmic elements in axonal terminals and preterminals. Multilamellar bodies, clusters of clear and dense core vesicles, increased numbers of secondary lysosomes, and an increase in the number of glycogen granules were observed in these structures. In astrocytes the amount of glycogen increased markedly in injected animals, but no other glial alterations were observed. The number of mast cells in the AP was greater in injected than in noninjected animals, both in the perivascular spaces (PVS) and in parenchymal locations. Cell processes in the PVS were occasionally observed to contain electron dense bodies, and degenerative changes were seen in supraependymal processes in some injected animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220623
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Osteodentine and vascular osteodentine of Anarhichas lupus (L.) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 135-146 
    Details
    ISSN: 1432-0878
    Keywords: Osteodentine ; Anarhichas lupus ; Ultrastructure ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Le tissu dentinaire d'Anarhichas lupus s'est révélé être une ostéodentine vasculaire. Les études en MET, MEB et diffraction X montrent l'hétérogénéité de ce tissu. L'aspect désordonné des fibres de collagène, incomplètement minéralisées (leur striation est encore bien visible), explique la complexité de la répartition des cristaux puisqu' elles en déterminent l'ordonnance. La minéralisation imparfaite du tissu, dont témoignait déjà la striation visible du collagène, est confirmée par l'analyse des poudres en diffraction X (la cristallinité de l'ostéodentine vasculaire est nettement inférieure à celle de la couche de tissu dentaire périphérique) et par l'examen en MET de haute résolution, aucun réseau cristallin n'ayant pu être mis en évidence. L'ostéodentine, l'os basal et l'os profond ont en commun une phase minérale, avec une organisation plus ou moins bonne, différente du système des apatites.
    Notes: Summary TEM, SEM and X-ray diffraction analysis demonstrate the heterogeneity of the dentinal tissue of Anarhichas lupus, a vascular osteodentine. The disordered aspect of collagen fibres, incompletely mineralized (the periodical striation being still visible), explains the scattered distribution of crystallites since they are responsible for their arrangement. The low degree of mineralization revealed by the visible collagen striation is confirmed by X-ray diffraction analysis (the crystallinity of vascular osteodentine being much lower than that of the peripheral dental tissue) as well as by high resolution TEM, since no lattice planes could be observed. Osteodentine, supporting bone and proper bone have in common a mineral phase, more or less organized, different from the apatite system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220625
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    The ultrastructure and renewal of the intestinal epithelium of the juvenile grasscarp, Ctenopharyngodon idella (Val.) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 181-200 
    Details
    ISSN: 1432-0878
    Keywords: Intestine ; Teleost ; Epithelium ; Renewal ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The intestinal absorptive epithelium of starved and fed fish has been studied electron microscopically. After feeding, cells of the proximal segment of the intestine show morphological characteristics of lipid absorption. Absorptive cells in the middle segment contain many pinocytotic vesicles in both fasted and fed specimens. Absorption of protein macromolecules is supposed to be one of the main functions of this part of the gut. In the most caudal part of the intestine, absorptive cells carry relatively few and short microvilli. The proximal and distal segments show structural indications of a function in osmoregulation. The renewal of the epithelium has been studied with light microscopic autoradiography, using tritiated thymidine. The intestinal mucosal fold epithelium represents a cell renewal system. The cells proliferate at the base of the fold and migrate towards the apex in 10–15 days at 20° C. The functional absorptive cells proved to be generally present in the intestinal epithelium, including the proliferative area. Undifferentiated cells have not been identified. The results will be compared with data on absorption of lipid and protein macromolecules in teleostean and mammalian intestines and with descriptions of the cell renewal system in the mammalian intestine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224364
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    The ultrastructure of the non-neurosecretory components in the brain of the midge, Chironomus riparius Mg. (Diptera: Nematocera) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 355-366 
    Details
    ISSN: 1432-0878
    Keywords: Neuron ; Glial ; (Insect, Chironomus riparius) ; Extracellular space ; Perineurium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the neural sheath, glial cells and neurons in the brain of the neoimaginal male Chironomus riparius is described. The neural sheath comprises a neural lamella and underlying perineurium. The neural lamella consists of an amorphous matrix in which fine fibrils occur. The perineurium is composed of two cell types forming a continuous layer around the brain. The subjacent cortical layer, composed of the cell bodies of neurons and glial cells, varies considerably in thickness and surrounds the centrally located neuropiles. Three types of glial cells are distinguished on the basis of their positions and appearances. Five types of neurons are described which differ in size and relative frequency of organelles. Four types of axons, including those of neurosecretory cells, are distinguished by their size and content.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224376
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    The posterior pituitary of the garden dormouse (Eliomys quercinus L.) (1978)
    Springer
    Cell & tissue research 188 (1978), S. 189-204 
    Details
    ISSN: 1432-0878
    Keywords: Neural lobe of hypophysis ; Hibernating mammals ; Ultrastructure ; Neurosecretory granules ; Whorls
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'ultrastructure de la posthypophyse du Lérot a été examinée à différents stades du cycle annuel de ce rongeur hibernant. Il n'a pas été observé de différences évidentes entre les stades étudiés, et sont donc présentées ici les caractéristiques générales retrouvées chez tous les animaux. Les axones neurosécréteurs et leurs terminaisons peuvent être divisés en deux catégories suivant l'aspect des grains de neurosécrétat et des microvésicules présents. Le premier type contient des grains arrondis, à contenu d'apparence homogène, avec des microvésicules rondes. Dans les autres axones, les grains sont de forme variable, souvent allongés, et leur contenu présente deux sortes d'organisations cristallines; les microvésicules y sont en majorité aplaties. Considérant comme improbable que cette dualité résulte seulement d'un artefact, trois hypothèses sont envisagées. La dualité d'aspect des grains peut être liée à leur contenu en hormone (ocytocine ou vasopressine); ou bien l'aspect des grains peut correspondre à leur degré de maturation. Il est possible aussi que ces explications soient toutes deux valables. Par ailleurs, les pituicytes du Lérot contiennent fréquemment un réticulum endoplasmique organisé en lamelles concentriques (whorls). La signification de ces formations reste pour l'instant obscure.
    Notes: Summary Ultrastructural examination of the posterior pituitary of the garden dormouse (Eliomys quercinus L.) was carried out at different times in the annual cycle of this hibernating rodent. Obvious differences between experimental groups have not been observed, and the results presented here must be considered as general features of the garden dormouse posterior pituitary. Neurosecretory axons and endings can be divided into two types, according to different aspects of neurosecretory granules (NSG) and microvesicles (MV). One type contains spherical NSG with homogeneous cores and round MV. In the other type, NSG have various, often elongated, shapes. Their content shows two types of crystalline structures and most of the MV have flattened aspects. As it is very unlikely that this duality in NSG is a result of an artefact of fixation, three hypotheses are presented as explanation. The duality of NSG might be related either to their hormonal content (oxytocin or vasopressin) or to their degree of maturation. Moreover, both explanations may be valid. In the species studied, pituicytes often contain concentric lamellar structures of the endoplasmic reticulum (whorls), the significance of which remains obscure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222630
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Ovarian follicles of normal NMRI mice and homozygous “Nude” mice (1978)
    Springer
    Cell & tissue research 188 (1978), S. 409-426 
    Details
    ISSN: 1432-0878
    Keywords: Ovary ; “Nude” mouse ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ovarian follicles of juvenile (15-day and 21-day old), pubescent (28-day old) and sexually mature (45-day old) “Nude” mice have been compared to those from normal NMRI mice of the same age and breeding groups. At the electron microscopical level, some differences were observed in both follicular cells and oocytes. In the follicular cells, the following alterations could be seen in the “Nude” ovaries: (1) the differentiation between clear and dark cells, normally not occurring before the age of 21 days, was already present in the 15-day old “Nude” mice and (2) the follicular intercellular spaces were frequently dilated, possibly because of a contraction of the cells, even in the small growing follicles of the bilaminar type in the athymic animals. The “Nude” oocytes could be characterized by (1) a precocious appearance and an early disappearance of the nuage material, (2) a nearly complete absence of micropapillae on the oolemma, (3) a dense and disseminated aspect of their Golgi complexes, (4) the presence of a large amount of multivesicular bodies and (5) of tiny (about 30 nm) dense membrane-bounded particles in their ooplasm. These differences are discussed in relation to the possible interference of congenital athymia with the development of the hypothalamo-pituitary-gonadal axis. However, the influence of the reduced immunological responsiveness of the “Nude” mice on their ovarian development cannot be excluded for animals raised in a normal — and consequently infected — environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219781
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Histological and cytological studies on the fat body of the cockroach Nauphoeta cinerea during the first reproductive cycle (1978)
    Springer
    Cell & tissue research 188 (1978), S. 481-490 
    Details
    ISSN: 1432-0878
    Keywords: Fat body ; Cockroach ; Reproductive cycle ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The central fat body of the ovoviviparous cockroach Nauphoeta cinerea was studied during the first reproductive cycle of the female by means of light microscopy, autoradiography and electron microscopy. Comparative studies in larval stages were also undertaken. The fat body of Nauphoeta contains a large amount of lipid droplets and the remaining cytoplasm is very scarce. The cytological cyclicity of the fat body is consistent with the known biochemical rhythms of vitellogenin production. The proteosynthetic apparatus appears about 3 days after imaginal ecdysis, along with vitellogenin. The ribosomal endoplasmic reticulum (RER) shows a tremendous increase by the 7th day of the first cycle. The most active period of vitellogenin production lasts from day 7 to day 12. The proteosynthetic apparatus then returns to an inactive stage and disappears. This inactive condition lasts to the end of the gestation period. The autoradiographic results are consistent with the cytological features.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219785
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    The ultrastructure and function of follicle cells in Foucartia squamulata (Herbst) (Curculionidae) (1978)
    Springer
    Cell & tissue research 189 (1978), S. 347-353 
    Details
    ISSN: 1432-0878
    Keywords: Vitelline membrane ; Chorion ; Ultrastructure ; Curculionidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The follicle cells of Foucartia squamulata are involved in the formation of both vitelline membrane and chorion. Precursors for these egg coverings are synthesized by the rough endoplasmic reticulum and condensed within dictyosomes. The vitelline membrane and the chorion appear on the oocyte surface simultaneously, which is an unusual phenomenon for insects. The follicular epithelium has not been found to contribute to vitellogenesis in the species under study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209282
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Oogenesis in Acerentomon gallicum Jonescu (Protura) (1978)
    Springer
    Cell & tissue research 189 (1978), S. 365-374 
    Details
    ISSN: 1432-0878
    Keywords: Previtellogenesis ; Oocyte ; Ultrastructure ; Acerentomon gallicum ; Protura
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary At the onset of previtellogenesis, the oocytes of Acerentomon gallicum begin to grow and increase their content of organelles. The nuage material in the oocytes at first increases in amount, then declines gradually to disappear completely from oocytes that have attained 50 μm in diameter. During the growth period, new dictyosomes, mitochondria and ribosomes appear. Numerous vesicles become detached from the cell membrane and subsequently fuse into cisternae, thus forming extensive complexes of the rough endoplasmic reticulum. In oocytes with diameters between 50 and 100 μm the Golgi complexes show a considerable increase in activity, and many lamellar bodies arise from mitochondria that have undergone specific transformation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209284
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Tormogen cell and receptor-lymph space in insect olfactory sensilla (1978)
    Springer
    Cell & tissue research 189 (1978), S. 549-554 
    Details
    ISSN: 1432-0878
    Keywords: Tormogen cell ; Receptor-lymph space ; Chemoreceptor ; Ultrastructure ; Histochemistry ; Calliphora (Insects)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary (1) The basiconic sensilla on the antennae of Calliphora resemble other insect epidermal sensilla; one or several bipolar sense cells are surrounded by three non-neural cells. (2) The apical cell membrane of the tormogen cell(one of the three accessory cells) forms microvilli coated internally with particles. (3) In the (extracellular) outer receptor-lymph space hyaluronic acid can be demonstrated histochemically. (4) Demonstration of non-specific alkaline phosphatase, Mg2+-activated ATPase, and the presence of mitochondria in the apical part of the tormogen cell suggest active transport processes through these cells into the outer receptor-lymph space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209140
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Kinetics of functional and morphological changes during decoupling and recoupling induced by glycerol in isolated muscle fibres of the crayfish (1978)
    Springer
    Cell & tissue research 192 (1978), S. 167-185 
    Details
    ISSN: 1432-0878
    Keywords: T-system tubules ; Glycerol procedure ; Structure-activity relationship ; Ultrastructure ; Astacus fluviatilis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of ultrastructural changes in the T-system of isolated muscle fibres of the crayfish by the glycerol procedure is described in correlation with the dissociation of excitation-contraction (E-C) coupling as well as with recoupling of the E-C link. The sequence of events in the process of disconnection of the tubules is as follows: dilation of the T-system tubules, disconnection of the constricted tubular segments from the surface membrane and from the T-system vesicle, disappearance of the lumen and its disintegration. The decoupled state is characterised by the presence of round vesicles uniformly distributed in the entire volume of the fibre. The volume of vesicles accounts well for the residual postglycerol volume increase (15%) of the muscle fibres. Functional and structural recovery can be induced by reapplication of glycerol to fibres decoupled and vesiculated with concentrations of glycerol≦300mmol · l-1 in crayfish saline. The restitution starts with the organisation of the material of the disintegrated connecting segment of the T-system tubule into small vesicles which coalesce to form the tubule from the vesicular site. At the same time the surface membrane is invaginated toward the vesicle, thus forming the tubule from the surface membrane site. Recovery starts already in the first minute after application of glycerol and is completed within approximately 15min.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231031
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Separation and maturation of gonadotrophs from 2A8 clonal cells in vitro (1978)
    Springer
    Cell & tissue research 189 (1978), S. 31-40 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary cell clone ; LHRH-Sepharose ; Gonadotrophs ; Hypertrophy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 2A8 clonal cells derived from the epithelium of Rathke's pouch of fetal rats were cultured in growth medium supplemented with fresh rat serum, median-eminence extract and l-thyroxine. Then, in order to isolate gonadotrophs, cyanogen bromide-activated Sepharose which was conjugated with LHRH (LHRH-Sepharose) was added to the culture medium. Fourteen days after incubation of 2A8 cells with LHRH-Sepharose, agranular and granular cells were rapidly bound to LHRH-Sepharose when fresh serum had previously been added in the medium. The cytoplasm of granular cells that were bound to LHRH-Sepharose contained spherical secretory granules (200–250 nm in diameter). These cells were similar in morphology to the FSH and LH gonadotrophs described by Kurosumi (1968). Moreover, many of them appeared as hypertrophied cells that resembled “castration” cells. These results demonstrate that LHRH conjugated to Sepharose can be used to separate gonadotrophs from other 2A8 cells, and it is suggested that the hypertrophy of some cells might be due to persistent stimulation by LHRH which is likely bound to receptors on the cell membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223119
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    The ultrastructure of the herring bodies in rats subjected to different experimental conditions (1978)
    Springer
    Cell & tissue research 189 (1978), S. 41-51 
    Details
    ISSN: 1432-0878
    Keywords: Herring bodies (rat) ; Colchicine ; Cold ; Neurosecretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A study of the morphology of Herring bodies of the posterior pituitary lobe of rats treated with colchicine and/or exposed to low temperatures has been performed. After treatment with colchicine (20 μg in distilled water injected intracisternally) a predominance of Herring bodies with a large number of small “synaptic-like” vesicles surrounded by neurosecretory granules is found. Exposures to low temperature (4–6° C) result in an increase in the neurosecretory material and the Herring bodies show many neurosecretory granules of different densities. After treatment with colchicine and subsequent exposure to low temperatures, the Herring bodies are characterized by having a great number of autophagic bodies which become more numerous as the length of the exposure is increased; later autophagic vacuoles and lamellar bodies become evident.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223120
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    The ultrastructure and histochemistry of the mesenteric connective tissue of the cockroach Periplaneta americana L. (Insecta, Dictyoptera) (1978)
    Springer
    Cell & tissue research 189 (1978), S. 91-107 
    Details
    ISSN: 1432-0878
    Keywords: Connective tissue sheath ; Periplaneta ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé La gaine conjonctive épaisse entourant l'intestin moyen de la Blatte Periplaneta americana a été étudiée en faisant appel à la microscopie photonique, électronique et l'histochimie. Cette couche conjonctive, reliée à l'épithélium mésentérique par une lame basale, traversée par des faisceaux musculaires, des trachées et des nerfs, contient de très nombreuses fibrilles de collagène, des fibrilles élastiques, des fibroblastes et des hémocytes. Au cours des premiers stades le matériel conjonctif est élaboré par des fibroblastes. Différentes réactions, en particulier le bleu alcian, la métachromasie et les digestions enzymatiques ont montré la présence de glycosaminoglycanes. La présence d'acide hyaluronique à tous les stades, l'apparition et l'augmentation des composés sulphatés ainsi que la présence de glycoprotéines ont été mises en évidence.
    Notes: Summary The thick layer of collagenous connective tissue around the mesenteron of the cockroach Periplaneta americana has been examined by light microscopy, electron microscopy and histochemical techniques. This sheath, connected to the mesenteric epithelium by a basal lamina and traversed by longitudinal and circular musculature, tracheae and nerves, contains numerous collagen fibrils, elastic fibers, fibroblasts and rare hemocytes. Development starts during the first instars with the production of connective tissue material by fibroblasts. Glycosaminoglycans have been observed with the use of various histochemical reactions, in particular alcian blue staining, metachromasia and enzymatic digestion. The reactions indicate the presence of hyaluronic acid in the various instars, the appearance and increase of sulphated components during development, and the presence of neutral glycoproteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223123
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    An ultrastructural study of periderm granules in the regenerating feather of the jungle fowl (1978)
    Springer
    Cell & tissue research 192 (1978), S. 319-326 
    Details
    ISSN: 1432-0878
    Keywords: Periderm granules ; Regenerating feather ; Ultrastructure ; Jungle fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Periderm granules in the support cells of regenerating feathers of mature male Jungle Fowls were studied ultrastructurally and histochemically. Histochemical results showed the absence of carbohydrate and lipid, and the presence of protein in the periderm granules. The periderm granules were measured at successive levels of feather regeneration. The mean size of the periderm granules increased significantly as the regenerating feather matured, and this observation was suggestive of a storage function, perhaps of surplus or waste protein. The cells in which the periderm granules are found also contain glycogen. There are numerous desmosomal junctions on their interdigitating plasma membranes. These transient cells may collect waste, provide nutrition, and serve as a protective barrier for the definitive cells of the regenerating feather.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220749
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    A further type of transient cytoplasmic organelle in human spermatids (1978)
    Springer
    Cell & tissue research 192 (1978), S. 359-361 
    Details
    ISSN: 1432-0878
    Keywords: Spermatids ; Human ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osmiophilic granules with surrounding vesicles resembling flower-like structures occur transiently during the differentiation of human spermatids. These organelles are incorporated into the residual bodies when mature spermatids are released from the germinal epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220752
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in the fat body of adult female Aedes aegypti in relationship to vitellogenin synthesis (1978)
    Springer
    Cell & tissue research 186 (1978), S. 499-506 
    Details
    ISSN: 1432-0878
    Keywords: Fat body ; Aedes aegypti ; Vitellogenin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the fat body of Aedes aegypti was followed from emergence through a blood meal. Changes in the volume of protein granules and lipid droplets were also examined. The relationship of these events to the known endocrinology of vitellogenin synthesis in mosquitoes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224938
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Leptomeric fibrils and T-tubule desmosomes in the Z-band region of the mouse heart papillary muscle (1978)
    Springer
    Cell & tissue research 188 (1978), S. 205-215 
    Details
    ISSN: 1432-0878
    Keywords: Myocardium ; Mouse ; Ultrastructure ; Leptofibrils ; Desmosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The papillary muscle of the heart of adult white mice is investigated. Intrafibrillarly located leptomeric fibrils, frequently encountered in the Z-band region of the myofibrils. The leptomeric fibrils are always running in a transverse direction and often in close proximity to the transverse tubules (which are also located at this level). There seems to be a close connection between the dense striae of the leptofibrils and the Z-bands of ordinary myofibrils. The leptomeric fibrils are spindle-shaped and have a length varying between 0.6 and 1.2 μm. The banding periodicity of the fibrils is approximately 0.16 μm. Occasionally desmosomes are observed in the T-tubule system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222631
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Ultrastrukturell-morphometrische Veränderungen des Ganglion spirale cochleae bei der Ratte nach Beschallung (1978)
    Springer
    European archives of oto-rhino-laryngology and head & neck 220 (1978), S. 193-199 
    Details
    ISSN: 1434-4726
    Keywords: Cochlear spiral ganglion ; Ultrastructure ; Morphometry ; Influence of broad band noise ; Cochleare Spiralganglien ; Ultrastruktur ; Morphometrie ; Beschallung mit Breitbandrauschen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Nach 40minütiger Beschallung des Ohres mit Breitbandrauschen von 105 dB SPL waren bei den Ratten elektronenoptisch noch keine sicheren Veränderungen an den Spiralganglienzellen festzustellen. Erst ultrastrukturell-morphometrisch ließen sich statistisch signifikante Veränderungen des Chondrioms und der Organellen des Leistungsstoffwechsels bei den granulären Spiralganglienzellen nachweisen. Der Volumenanteil der Mitochondrien im Einheitsvolumen Zytoplasma nahm zu. Auch das Volumen und die Oberfläche des RER sowie das Volumen der freien Ribosomen und der Nucleolen vergrößerten sich im Einheitsvolumen Zytoplasma bzw. pro Zelle. Die physiologische Bedeutung dieser Veränderungen wurde diskutiert. Die Resultate zeigen u. a., daß Veränderungen der Cytoarchitektur in den granulären Spiralganglienzellen morphometrisch früher als elektronenoptisch registriert werden können.
    Notes: Summary The comparison of ultrastructural and ultrastructural-morphometric findings in spiral ganglion cells subsequent to broad band noise with 105 dB SPL over a period of 40 min demonstrates that there are morphometric changes of the cytoarchitecture of granular ganglion cells even without evident ultrastructural changes. Morphometric analyses shows a significant extention of the volume proportion of mitochondria per unit volume cytoplasm. The volume and the surface of the rough endoplasmic reticulum, the volume of the free ribosomes and the average single volume of the nucleoli increase per granular ganglion cell. The physiologic significance of these changes is discussed. The results show that changes of the cytoarchitecture of granular spiral ganglion cells are earlier detected by morphometry than by ultrastructural description.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00457487
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Reduction of 5,6-Dimethylidene-exo-2,3-epoxynorbornane with Metal Hydrides. Efficient syntheses of 6-methyl-5-methylidene-anti-3- nortricyclanol and of 2,3-dimethylidene-anti-7-norbornanol (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 732-740 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 5,6-Dimethylidene-exo-2,3-epoxynorbornane (1) is reduced slowly by LiAlH4 in boiling tetrahydrofuran (THF) and furnishes a mixture of 5,6-dimethylidene-exo-2-norbornanol (2), 2,3-dimethylidene-anti-7-norbornanol (3) and principally 6-methyl-5-methylidene-anti-3-nortricyclanol (4). The yield of 4 is the highest for low initial concentrations of LiAlH4; it decreases in favour of alcohols 2 and 3 at high concentration of LiAlH4. The reduction of 1 with AlH3 in THF yields 3 as the major product, thus revealing an efficient synthesis of 7-substituted-2, 3-dimethyl-idenenorbornane derivatives. No alcohol 2could be isolated by LiEt3BH reduction of 1. LiAlD4 reduces 1 into the monodeuterated alcohols 2-d, 3-d and 4-d. The deuterium label is found in the endo-position at C (3) in 2-d, in the exo-position at C(5) in 3-d and in the methyl group of the tricyclic alcohol 4-d. Mechanistic limits for the formation of 2, 3 and 4 are discussed briefly.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610221
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Tris (methylidene)-cyclopropane (“[3]Radialene”) Part 1. Enthalpy of formation and strain energyDedicated to Prof. C.A. Grob on the occasion of his sixtieth birthday (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 741-753 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The enthalpy of formation of tris(methylidene)-cyclopropane (“[3]radialene”, 1) has been determined as ΔHfO = 396 ± 12 kJ mol-1 from three fragmentation reactions of its molecular ion 1+ formed from 1 by photoionisation using synchrotron radiation. Comparative electron impact measurements using conventional mass spectrometry were also performed. A treatment of the latter data is described which leads to satisfactory agreement with the photoionization data. The experimental value of ΔHfO(1) is compared with various theoretical estimates. The strain energy of 1 is calculated to be 226.3 kJ mol-1. Linear extrapolation of this quantity from the increase of strain in passing from cyclopropane to methylidenecyclopropane yields 282.4 kJ mol-1. The discrepancy between these values, already predicted by Dewar and Baird ten years ago from theoretical calculations, is discussed on the basis of maximum overlap considerations. The enthalpy of formation of bis(methylidene)cyclopropane is predicted to be ΔHfO= 309 kJ mol-1.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610222
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Diterpenoide Drüsenfarbstoffe aus Labiaten: 6 neue p-Chinomethane aus Plectranthus parviflorus WILLD (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 709-715 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Leaf-gland Pigments: 6-Novel p-Quinomethanes of the Abietane Series from Plectranthus parviflorus WILLDThe above mentioned plant accumulates in its red coloured leaf-glands a complex mixture of strongly dehydrogenated abietanols. They were separated (with difficulties) to yield 6 novel compounds. Spectroscopic and chiroptic data show them to be esters of either 11, 19-dihydroxy- or 2 α, 11-dihydroxy-abieta-5, 7, 9 (11), 13-tetraen-12-one 2a and 3a, respectively. Specifically, the 19-O-p-hydroxybenzoate (2d) parvifloron C, the 19-O-vanilloate (2c) parvifloron B, the 19-O-p-hydroxy-benzoate (2d) parvifloron C, the 19-O-3′,4′-dihydroxybenzoate (2e) parvifloron E, the 2 α-O-p-hydroxybenzoate (3b) parvifloron D, and the 2 α-O-3′,4′-dihydroxy-benzoate (3c) parvifloron F. Reduction by LiAlH4 splits the ester function and reduces the p-quinomethane to a colourless pyrocatechol derivative which, by air oxidation, regenerates the red p-quinomethane system of 2a and 3a.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    A New Derivation of the Electric Field Dependence of Optical Absorptions of Isotropic SamplesIn Memoriam Prof. Dr. Heinrich Labhart (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 772-782 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A calculation of the modification of the optical absorptions of an isotropic sample by a uniform external electric field is presented. The induced orientational anisotropy, the Stark shift and the field. dependence of the transition moment are taken into account up to the second order in the field. The final expressions differ in the contributions from the transition polarizabilities from previous results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610225
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Tris (methylidene)-cyclopropane (“[3]Radialene”). Part 2. Electronic states of the molecular cation and revised UV.-absorption spectrum of the parent neutralPart 1: [1] (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 754-761 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The photoelectron spectrum of tris (methylidene)-cyclopropane 1 (“[3]radialene”) is reported and the electronic states of 1+ assigned. Jahn-teller activity in the degenerate states of 1+is discussed. Differences in the Franck-Condon profile of the first PE band and the Rydberg series in the Vacuum-UV./UV. absorption spectrum indicate for the Rydberg series (n=3) a 1A″2-species, which supports earlier tentative proposals. The high intensity absorption in the 5.5 eV-6 eV energy range of the latter spectrum recorded earlier are definitely due to impurities. The vibrational fine structure of a weak band system around 5.5 eV in our spectrum suggests for this transition S0→S2(1A′1), which is dipole forbidden but borrows intensity from S1(1E′) trough vibronic coupling via an e′-mode. From vapor pressure measurements ε(λmax=289 nm) = 9390± 1170 for gaseous 1 was found.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610223
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Vibrational Spectra of Anhydrous Lanthanum, Europium, Gadolinium, and Dysprosium Nitrates and Oxinitrates (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 762-771 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: IR. and Raman spectra of LnONO3 (50-4,000 cm-1, Ln=La, Gd, Eu, and Dy) are reported and discussed. The low frequency region of the spectra reflects the cubic structure of these compounds. The dimensions of the cubic unit cells determined by X-Ray powder diagrams are: 12.81 ± 0.05 Å for EuONO3, 12.69 ± 0.05 Å for GdONO3, and 12.67 ± 0.05 Å for DyONO3. The vibrational frequencies of the nitrato group are consistent with a bidentate nitrate of C2v symmetry. The synthesis of anhydrous Ln (NO3)3 (Ln=La, Gd, Eu, and Dy) by dehydration of the corresponding penta- or hexahydrates is described. The IR. and Raman spectra (50-4,000 cm-1) are analysed. Splitting of the bands point to a complex structure of these compounds. All six vibrational modes of the nitrato group are observed and the data are again consistent with bidentate NO-3 moieties. Finally, an analytical control of the purity of Ln (NO3)3 is suggested.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610224
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Synthese von 3-Dimethylamino-3a,4,5,7a-tetrahydro-1H-iso-indol-1-onen durch intramolekulare Diels-Alder-Reaktion (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 815-821 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of 3-Dimethylamino-3a,4,5, 7a-tetrahydro-1H-isoindol-1-ones by Intramolecular Diels-Alder ReactionThermolysis of N2-acylamidines, the acyl group of which derives from an α,β,γ,δ-unsaturated carboxylic acid (2, 5-7), yields 3-dimethylamino-3a,4,5,7a-tetrahydro-1H-isoindol-1-ones (3,8-10, Schemes 1 and 3) in 63-78%. Only the thermodynamically controlled cis-fused ring system is formed. The starting materials are readily available by the reaction of 3-dimethylamino2H-azirines (1 and 4) and carboxylic acid chlorides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610228
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Reaktionen von Aziridino-nitrenen: Herstellung von polycyclischen Bisaziridinen und von 1,2-Bisaziridino-diazenenVorgetragen in der Versammlung der Schweizerischen Chemischen Gesellschaft in Bern am 7. Oktober 1977.Zum Andenken an Prof. Dr. Heinrich Labhart (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 795-814 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of Aziridino-nitrenes: Synthesis of Polycyclic Bisaziridines and 1,2-Bisaziridino-diazenesVorgetragen in der Versammlung der Schweizerischen Chemischen Gesellschaft in Bern am 7.Oktober 1977.7-Amino-7-azabicyclo[4.1.0]-3-heptene (11b), cis-9-amino-9-azabicyclo[6.1.0]-nonane (12b), cis-9-amino-9-azabicyclo[6.1.0]-(4Z)-nonene (13b), as well as exo- and endo-3-amino-3-azatricyclo[3.2.1.02,4]-6-octene (14b and 15b) were synthesized by addition of oxidatively generated phthalimido-nitrene (6) to 1,4-hexadiene, (Z)-cyclooctene, (1Z,5Z)-cyclooctadiene, and bicyclo[2.2.1]heptadiene, respectively, followed by hydrazinolysis of the corresponding N-phthalimido-aziridines 11a-15a.Lead tetraacetate oxidation of the two unsaturated N-amino-aziridines 11b and 15b at -70° yielded diazapolycyclic structures by intramolecular addition of the intermediate aziridino-nitrenes 11c and 15c to the δ, ε-situated C, C-double bond; the products obtained in good yields were 1,5-diazatetracyclo [3.3.0.02,8. O4,6]-octane (16) and 3,7-diazapentacyclo [3.3.1.02,4.03,7.06.8] nonane (17), respectively Oxydation of the unsaturated N-amino-aziridine 13b under the same conditions did not cause intramolecular addition of the nitrene 13c to the ε, ζ-situated C, C-double bond; instead 1,2-bis (cis-9-azabicyclo [6.1.0]-(4Z)-nonen-9-yl)-diazene (20) was obtained in low yield and (1Z, 5Z)-cyclooctadiene as the main product. Both products can be rationalized as derived from the intermediate nitrene 13c with 13b and the olefine as the result of a fragmentation of 13c under extrusion of N2. As. expected, oxidation of the saturated N-amino-aziridine 12b led to the 1,2-bisaziridino-diazene 21 and (Z)-cyclooctene in a ratio of 4:6. Surprisingly, oxidation of 7-amino-7-azabicyclo [4.1.0]-heptane (10b) produced only fragmentation of the corresponding nitrene 10c to cyclohexene. Finally, oxidation of the exo-N-amino-aziridine 14b yielded a complex not yet resolved product mixture in low overall yield. Attempts to add the oxidatively generated aziridino-nitrene 12c to cyclohexene, methyl acrylate, and dimethylsulfoxide were without success.Heating the 1,2-bisaziridino-diazenes 20 and 21 at their respective m.p. temperatures caused thermal fragmentation to occur with evolution of nitrogen. The bisaziridines 26 and 28 as well as the aziridines 27 and 29, respectively, were isolated. These products could be the result of a radical pathway, whereas a small amount of (Z)-cyclooctene, also generated in the thermolysis of 21, might be formed by a competing cheletropic pathway.The 1H-NMR-spectra of the derivatives of cis-9-azabicyclo[6.1.0]nonane, namely of 12a, 12b, 21, 28 and 29, showed signals for some of the aliphatic protons which were separated from the others at relatively low field (around 2.5-1.8 ppm). These signals accounted for 4 (with 12b for 2) protons in each of the cis-9-azabicyclo[6.1.0]nonane subunits, i.e. more than the 2 expected for the aziridine methine protons. The additional signals must be assigned to methylene protons (2 or even 4 of them) probably situated on the other side of the eight membered ring and deshielded by the motion-average proximity to the aziridine nitrogen atom.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610227
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Über die Carotinoide Flavoxanthin und Chrysanthemaxanthin: 1H-NMR.-, 13C-NMR.- und Massen-Spektren und absolute Konfiguration. (Kritische Überprüfung veröffentlichter chemischer und physikalischer Daten)Aus der geplanten Dissertation von H.C. (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 783-794 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Carotenoids Flavoxanthin and Chrysanthemaxanthin: 1H-NMR., 13C-NMR. and Mass Spectra, Absolute Configuration, Survey of Published DataVery pure flavoxanthin (1) and chrysanthemaxanthin (2) have been reisolated from flower heads of Taraxacum officinale. Both compounds were characterized by chromatographic, chemical and chiroptical data and extensive NMR. measurements. Examination of many published data on 1 and 2 led to the conclusion that flavoxanthin has often been mistaken for chrysanthemaxanthin and vice versa.Chemical degradation of 1 and 2 to (-)-loliolide (5) coupled with NMR. evidence (ASIS, spin-decoupling, NOE) allowed the assignment of the absolute configurations of 1 and 2. Thus (+)-flavoxanthin is (3S,5R,8R, 3′R,6′R)-5, 8-epoxy-5, 8-dihydro-β, ε-carotene-3, 3′-diol and (+)-chrysanthemaxanthin its C(8)-epimer.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610226
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Synthese und Chiralität von (5S, 6R)-5,6-Epoxy-5,6-dihydro-β,β-carotin und (5R, 6R)-5,6-Dihydro-β,β-carotin-5,6-diol, einem Carotinoid mit ungewöhnlichen Eigenschaften (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 822-831 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Chirality of (5S,6R)-5,6-Epoxy-5,6-dihydro-β,β-carotene and (5R,6R)-5,6-Dihydro-β,β-carotene-5,6-diol, a Compound with Unexpected Solubility CharacteristicsWittig-condensation of azafrinal (1e) with the phosphorane derived from 7 leads to a (1:3)-mixture of (E)-9′- and (Z)-9′-β,β-carotene-diol 3, from which pure and optically active 3 ((5R,6R)-5,6-dihydro-β,β-carotene-5,6-diol) has been isolated as bright violet leaflets, m.p. 168°. Due to the trans-configuration of the diol moiety and to severe steric hindrance, hydrogen bonding is reduced to such an extent, that 3 behaves much more as a hydrocarbon than as a diol. There is good evidence that the so-called ‘β-oxycarotin’ obtained by Kuhn & Brockmann [15] by chromic acid oxidation of β, β-carotene is the corresponding racemic cis-diol. 3 has been converted into (5S, 6R)-5,6-epoxy-5.6-dihydro-β,β-carotene (4), m.p. 156°. This transformation establishes for the first time the chirality of a caroteneepoxide (without other O-functions).Full spectral and chiroptical data including a complete assignement of 13C-chemical shifts for azafrin methyl ester and 3 are presented.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610229
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Studies on the Synthesis of (2R,4′R,8′R)-α-Tocopherol Alternative Syntheses of 2-Chroman-acetic Acid Intermediates (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 837-843 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: As an extension of previous studies on the total synthesis of (2R,4′R,8′R)-α-tocopherol (1) [1] [2], (S)-(-)-2-(6-benzyloxy-2,5,7,8-tetramethylchroman)acetic acid (6), a pivotal intermediate, possessing the absolute configuration required for construction of 1 was prepared by optical resolution of the racemic modification 11. the latter substance was obtained by two routes, one emanating from the hydroxy acetal 7 [1] and the other based upon the Lewis acid mediated cycloaddition of trimethylhydroquinone to rac.-3-hydroxy-3-methylpent-4-en-l-yl acetate (16) giving rac. ethyl 2-(6-hydroxy-2,5,7,8-tetramethyl-chroman)acetate (12).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610231
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Etude thermodynamique des complexes de transfert de charge du type n-σ* en solution Complexes de la quinoléine et de quinoléines substituées avec I2, ICI et IBr (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 832-836 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermodynamic study of charge transfert complexes (n-σ*) in solutionCharge transfer complexes of quinoline and substituted quinolines (donors) with iodine, iodine chloride, and iodine bromide (acceptors) have been studied spectrophotometrically in CCl4. The 1:1 stoechiometry of these complexes was verified by means of the continous variations method and the appearance of isosbestic points. Simultaneous determination of the equilibrium constant and enthalpy of adduct formation was carried out by calorimetry.It was observed for every donor that the equilibrium constants of the complexes studied increase with the strength of the acceptors. A linear correlation between enthalpy of adduct formation and donor strength was obtained only for the complexes Donor ICI.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610230
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Synthesis of Three Jasmin Constituents via a Central IntermediateThese results were reported by P. Dubs at the Autumn session of the Swiss chemical Society (Oct. 20, 1973) in Lugano. (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 990-997 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses of jasmone (1), methyl jasmonate (3) and γ-jasmolactone (2) are reported, (Z)-nona-1, 6-dien-3-one (4) serving as common intermediate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610307
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Über die Herstellung von Äther der enantio-14, 15-Dinorlabdan-Reihe aus EperusäureIm Englischen: Eperuic acid. (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1004-1010 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Conversion of Eperuic Acid into Ethers of the enantio-14, 15-Dinorlabdane Series5 and 6 are strongly odiferous substances of the ambra-type. Their enantiomers 7 and 8, hitherto unknown, have been synthesized from eperuic acid (4) and their olfactory properties compared with those of 5 and 6. 4 was esterified by CH2N2 and dehydrogenated with (C6H5Se)2/H2O2 to the α,β-unsaturated ester 9 (61%). Oxidation by KMnO4 in acetone yielded the ketone 3 (60%). Epoxidation followed by treatment with acid converted 3 into the acetals 7 (61%) and 8 (14%). 7 and 8 differ from 5 and 6 in odor intensity, and 6 and 8 show slightly different odor quality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610309
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Partial Syntheses of Methyl Dehydrojasmonate and TuberolactoneThese results were reported by P. Dubs at the Autumn session of the Swiss Chemical Society (Oct. 8, 1977) in Berne. (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 998-1003 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The natural products methyl dehydrojasmonate (1) and tuberolactone (2) have been synthesized from methyl jasmonate (3) and jasmolactone (4) resp., via sulfenylation-sulfoxide pyrolysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610308
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Vergleichende Untersuchung von Reaktivitäten und Ionenstrukturen beim monomolekularen Abbau isomerer Hydroxyzimtsäuremethylester unter Elektronenbeschuss (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1017-1024 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Comparative investigation of reactivities and ion structures upon electron impact induced degradations of the isomeric hydroxy cinnamic acid methyl estersBy analysis of energy release data in metastable peaks it is shown that m- and p-hydroxy cinnamic acid methylesters retain specific structural features upon degradation under electron impact, although their spectra are very similar and the shapes of the metastable peaks due to the initial methoxy cleavage are identical. A pronounced charge radical localization in the molecular ion is indicated. The o-isomer is found to yield a coumarin type structure by elimination of methanol, whose further degradation by decarbonylation involves at least three different mechanisms. The resulting ion structures are different from benzofuran.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610311
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Selective Removal of the o-Nitrophenylsulfenyl Protecting Group in Peptide Synthesis (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1086-1090 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Thiopyridone (2-mercaptopyridine, 1) was found to be a very suitable reagent for removing the Nα-o-nitrophenylsulfenyl (NPS-) group in both conventional and solid-support peptide synthesis. A 3- to 5-molar excess of the reagent together with an equivalent amount of glacial acetic acid in methanol, dimethylformamide, or methylene chloride produces the soluble, stable mixed disulfide, 2-nitrophenyl 2-pyridyl disulfide (2), and the Nα-deprotected amino-acid or peptide. The yields are quantitative in less than 5 min if all educts are dissolved, in about 20 to 30 min in solid-support synthesis. No modifications of either the indole side-chain of tryptophan or of a series of side-chain protecting groups, in particular of the t-butyl type, are produced. No adverse side-reactions (insoluble disulfides) were observed. The procedure is illustrated with a series of amino-acid derivatives and with the solid-support synthesis of [5-leucine]-enkephalin.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610318
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Anti- and syn-Tricyclo [4.2.1.12,5]decaneThe anti/syn-nomenclature indicates the relative position of the two methylene bridges.. Preliminary communication (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1107-1109 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The two novel tricyclic C10H16 compounds anti- and syn-tricyclo [4.2.1.12,5]- decane (16 and 17, respectively) were synthesized starting either from the photodimer 2 (anti) or the two cycloaddition products 8 (anti) and 9 (syn).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610321
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    The Condensation of Cyclic Aminoketones, Cyclohexanone and Cyclohexane-1,4-dione with some Phenolic Ethers in Polyphosphoric Acid (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1110-1114 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The title condensations gave respectively: gem-bisarylated cyclic amines 3a-k or monoarylated unsaturated cyclic amines 4a-g, 1,3-bisarylated cyclohexadienes 6a, 6b, the condensed bicyclo [2,2,2]-octane 8. In addition the aromatic ketone 9 gave the fluorenone 10 on treatment with polyphosphoric acid (PPA).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610322
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Nickel-katalysierte Synthese von α-Nornicotin-Derivaten. Vorläufige MitteilungDr. G. Schetty zum 65. Geburtstag gewidmet (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1115-1117 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nickel-catalysed Synthesis of α-NornicotinesSchiff's bases 1 and butadiene generally co-oligomerize on nickel catalysts to yield octatrienyl-substituted amines 2 and octadienyl-substituted imines 3.Schiff's bases 4 and 5, on the other hand, react with 1, 3-dienes to give new [3+2]-cycloadducts 6. In addition to the appropriately functionalized α-nornicotine derivatives some higher oligomers are formed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610323
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Copper Catalysed Oxygenation of Bis (2-pyridyl) methane and 6-Methyl-bis (2-pyridyl)methane to the Corresponding Ketones (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1097-1106 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ligands (L) bis (2-pyridyl) methane (BPM) and 6-methyl-bis (2-pyridyl)methane (MBPM) form the three complexes CuL2+, CuL22+, and Cu2L2H-22+ with Cu2+. Stability constants are log K1 = 6.23 ± 0.06, log K2 = 4.83 ± 0.01, and log K (Cu2L2H-22+ + 2H2+ ⇌ 2 CuL2+) = -10.99 ± 0.03 for BPM and 4.56 ± 0.02, 2.64 ± 0.02, and -11.17 ± 0.03 for MBPM, respectively. In the presence of catalytic amounts of Cu2+, the ligands are oxygenated to the corresponding ketones at room temperature and neutral pH.With BPM and 2,4,6-trimethylpyridine (TMP) as the substrate and the buffer base, respectively, the kinetics of the oxygenation can be described by the rate law \documentclass{article}\pagestyle{empty}\begin{document}$${{ - {\rm d}\left[{{\rm O}_2 } \right]} \mathord{\left/ {\vphantom {{ - {\rm d}\left[{{\rm O}_2 } \right]} {{\rm dt}}}} \right. \kern-\nulldelimiterspace} {{\rm dt}}} = {{k_1 \left[{{\rm CuL}_2^{2 + } } \right]} \mathord{\left/ {\vphantom {{k_1 \left[{{\rm CuL}_2^{2 + } } \right]} {\left[{{\rm H}^ + } \right]}}} \right. \kern-\nulldelimiterspace} {\left[{{\rm H}^ + } \right]}} + k_2 \left[{{\rm CuL}_2^{2 + } } \right]\left[{{\rm TMP}} \right] + {{k_3 \left[{{\rm CuL}^{2 + } } \right]} \mathord{\left/ {\vphantom {{k_3 \left[{{\rm CuL}^{2 + } } \right]} {\left[{{\rm H}^ + } \right]}}} \right. \kern-\nulldelimiterspace} {\left[{{\rm H}^ + } \right]}} + {{k_4 \left[{{\rm Cu}_2 {\rm L}_2 {\rm H}_{ - 2}^{2 + } } \right]} \mathord{\left/ {\vphantom {{k_4 \left[{{\rm Cu}_2 {\rm L}_2 {\rm H}_{ - 2}^{2 + } } \right]} {\left[{{\rm H}^ + } \right]}}} \right. \kern-\nulldelimiterspace} {\left[{{\rm H}^ + } \right]}}$$\end{document} with k1 = (5.9 ± 0.2) · 10-13 mol l-1 s-1, k2 = (4.0 ± 0.6) · 10-4 mol-1 ls-1, k3 = (1.1 ± 0.1) · 10-12 mol l-1 s-1, and k4 = (9 ± 2) · 10-14 mol l-1 s-1.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610320
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Nickel-katalysierte Isomerisierung von Butadien-Hydrazon-Misch-Oligomeren. Vorläufige MitteilungDr. G. Schetty zum 65. Geburtstag gewidmet (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1118-1121 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nickel-catalysed Isomerization of Unsaturated AzocompoundsUnsaturated azocompounds, produced by the nickel-catalysed reaction of butadiene with hydrazones, can be isomerized in presence of the same nickel catalyst. The influence of nickel concentration, temperature and structure of the azocompound on this rearrangement is described.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610324
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...