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  • 1985-1989
  • 1970-1974  (2,046)
  • 1920-1924  (551)
  • 1973  (2,046)
  • 1920  (551)
  • Inorganic Chemistry  (1,188)
  • Cell & Developmental Biology  (566)
  • Industrial Chemistry  (410)
  • Engineering  (189)
  • Electron microscopy  (149)
  • Physical Chemistry  (95)
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Material
Years
  • 1985-1989
  • 1970-1974  (2,046)
  • 1920-1924  (551)
Year
Keywords
  • 101
    Electronic Resource
    Electronic Resource
    Ultrastructure of the pseudohermaphrodite rat testis (1973)
    Springer
    Cell & tissue research 140 (1973), S. 473-479 
    Details
    ISSN: 1432-0878
    Keywords: Testicular feminization ; Rat ; Leydig cells ; Sterility ; Androgens, Steroids ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The interstitial cells of the pseudohermaphrodite rat testis are both hypertrophic and hyperplastic. The cytoplasm is characterized by smooth endoplasmic reticulum which is abundant and variable in form. Mitochondria are numerous and large with tubular cristae and occasional inclusions. Structural features of the Leydig cells indicate potential for increased steroid synthesis. The presence of large numbers of mast cells in the intertubular area is confirmed. Small seminiferous tubules lack advanced germinal elements. Additional connective tissue and myoepithelial layers produce a thickening of the limiting membrane. Some myoepithelial cells are atypical with an electron translucent cytoplasm and nuclei with dense peripheral chromatin. No spermatogenic cells beyond the cap phase of the spermatid are observed. The cytoplasm of Sertoli cells contains large lipid droplets and degenerating germ cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306674
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  • 102
    Electronic Resource
    Electronic Resource
    Evidence for basal secretion in the subcommissural organ of the adult rabbit (1973)
    Springer
    Cell & tissue research 142 (1973), S. 223-239 
    Details
    ISSN: 1432-0878
    Keywords: Subcommissural organ (SCO) ; Basal secretion, Lateral secretion ; Extracellular spaces (ECS) ; Innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphological evidence is presented supporting the possibility of basal secretion into hypendymal capillaries of the adult rabbit subcommissural organ (SCO). The synthetic apparatus of the SCO cell is described as well as the heterogeneous granules and vesicles which are concentrated in the basal processes bordering a widened perivascular space. The origin of the electron dense granules, of which two fairly distinct subgroups are found, is discussed. A binding of secretory sacs to the lateral plasma membrane is seen. The possibility of a lateral secretion is supported by the presence of a system of extracellular channels between SCO cells which are filled with a flocculent material resembling that of the secretory sacs. Nerve perikarya which are separated from the SCO by only a few glial fibers are demonstrated. Synapses are described in nerve fascicles bordering on the hypendymal capillaries. The possibility of an innervation of the hypendymal region is discussed as well as possible nervous connections with the pineal gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307034
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  • 103
    Electronic Resource
    Electronic Resource
    Effects of colchicine on release of neurosecretory material from the posterior pituitary gland of the rat (1973)
    Springer
    Cell & tissue research 142 (1973), S. 443-464 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Posterior Pituitary gland ; Colchicine ; Axoplasmic flow ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of colchicine on the release of neurosecretory material from the posterior pituitary gland was investigated in the rat in vivo and in vitro. Colchicine was administered subarachnoidally when neurophysin, radiolabelled by injection of (35S) cysteine into the supraoptic nucleus, had accumulated in the neural lobe. Dehydration for 3 days of non-colchicine-treated rats was followed by a 100% reduction of neurophysin-bound radioactivity. When colchicine was given prior to dehydration, the reduction of radioactive neurophysin was less marked. Colchicine treatment alone was likewise followed by a lowering of protein-bound radioactivity in the neural lobe, which may indicate that colchicine, in addition to blocking the rapid axonal transport of neurosecretory material, also impedes the slow transport. The release of radioactive neurophysin in response to depolarizing concentration of potassium in vitro was diminished in the presence of colchicine, the reduction being most pronounced after colchicine treatment in vivo. The biochemical data prove the view that colchicine inhibits the release of neurosecretory material from the neural lobe. The ultrastructural findings support the biochemical data. Thus, colchicine treatment alone or followed by dehydration induced a marked increase in the number of organelles, especially of mitochondria and dense bodies. There was a marked increase in the number of enlarged axons filled with dammed organelles in the infundibulum and neurohypophysis. There was an accumulation of dense core vesicles and microvesicles in the axonal terminals in the neurohypophysis after treatment with either colchicine or colchicine followed by dehydration, which indicates an impediment of the release process. Dehydration alone induced a depletion of the dense core vesicles in the terminals. Out from the combined biochemical and ultrastructural findings possible mechanisms for the action of colchicine are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306709
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  • 104
    Electronic Resource
    Electronic Resource
    Identification of adenohypophysiotropic neurohormone producing neurosecretory cells in Rana temporaria (1973)
    Springer
    Cell & tissue research 142 (1973), S. 479-513 
    Details
    ISSN: 1432-0878
    Keywords: Median eminence (Frog) ; Tubero-hypophysial system ; Neurosecretory axon types ; Release phenomena ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of electron microscopy, in the median eminence of Rana temporaria, the terminal arborizations of axons of six different types of neurosecretory cells, located in the pars ventralis of the tuber cinereum, were identified. In addition, phenomena connected with the release of neurosecretory material from the axon terminals of these neurosecretory cells into the blood capillaries of the median eminence are described. Preliminary results suggested the existence, in the median eminence, of additional different neurosecretory axon types which could also belong to corresponding neurosecretory cell types probably located in the apical part of the pars ventralis of the tuber cinereum. Moreover, in the external region of the normal median eminence, separate monoaminergic nerve fibres were tentatively identified. Arguments are adduced which plead (1) against the assumption that the ependyma or the pituicytes of the median eminence could produce adenohypophysiotropic hormones; (2) against the inference that the ependymal cells of the median eminence might be involved in the transport of adenohypophysiotropic hormones from the cerebrospinal fluid into the blood capillaries of the median eminence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306711
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  • 105
    Electronic Resource
    Electronic Resource
    Topochemischer Nachweis von carbonylhaltigen Verbindungen im Thymus (1973)
    Springer
    Cell & tissue research 142 (1973), S. 465-477 
    Details
    ISSN: 1432-0878
    Keywords: Rabbit thymus ; Ketosteroids ; Granulated cells ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Topochemisch konnten im Kaninchenthymus Ketosteroide nachgewiesen werden, für deren Vorhandensein die chemische Analyse von Thymuslipidextrakten Hinweise ergeben hatte. Die Darstellung der Ketosteroide erfolgte mit der NAHD-Reaktion (Camber, 1949). Diese Befunde dürften als spezifisch gelten, da eine Verfälschung durch freie Gewebsaldehyde, Plasmalogene (Gomori, 1952) und Corticosteroide (Khanolkar et al., 1958) ausgeschlossen wurde. Mit Hilfe der Camber-Methode konnten Granula bestimmter Zellen des Kaninchenthymus selektiv dargestellt werden, die auf Grund morphologischer Kriterien in zwei Gruppen unterteilt wurden. Die Zellen liegen im gesamten Thymusparenchym sowie im Bindegewebe der Septen und der sogenannten „Kapsel“. Prädilektionsorte stellen die Umgebung der Hassallschen Körperchen, die Mark-Rinden-Grenze, der intra- und perivasale Raum sowie die subkapsuläre Zone dar. Beide Zellgruppen sind Sudan III-, PAS- und Eosin-positiv, besitzen eine ausgeprägte gelbgrüne Eigenfluoreszenz und können differentialdiagnostisch gegen Mastzellen abgegrenzt werden. Elektronenmikroskopisch zeigen beide Zellgruppen zahlreiche Übereinstimmungen mit Reifestadien eosinophiler Knochenmarkszellen.
    Notes: Summary Ketosteroids were demonstrated topochemically in the rabbit thymus following indications given by chemical analysis of thymus lipid extracts. They were revealed by means of the NAHD-reaction (Camber, 1949). The results are thought to be specific, because adulteration by free tissue aldehydes, plasmalogens (Gomori, 1952) and corticosteroids (Khanolkar et al., 1958) can be excluded. The Camber-method selectively reveals the presence of two groups of morphologically differentiable granules in specific rabbit thymus cells which are distributed throughout the entire thymic parenchyme as well as in the connective tissue of the septa and the in so-called “capsule”. They are mainly seen in the vicinity of Hassall's bodies, in the zone between medulla and cortex, the intra- and perivascular space and in the subcapsular space. Both cell groups are Sudan III-, PAS- and eosin-positive, show intensive yellow-green primary fluorescence and can be distinguished from mast cells by differential diagnosis. Electron microscopy reveals that both cell groups show many similarities with the maturation phase of bone marrow eosinophils.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306710
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  • 106
    Electronic Resource
    Electronic Resource
    New results on the ultrastructure of frog rod outer segments (1973)
    Springer
    Cell & tissue research 143 (1973), S. 45-52 
    Details
    ISSN: 1432-0878
    Keywords: Frog (Retina) ; Rod, Outer Segments ; Method of preparation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fibrils are demonstrated as an ultrastructural component in ultrathin sections of frog rod outer segments by a modified method of preparation which leads to partial contrast reversal. The relationship between these results and those obtained by conventional treatment leading to positive contrast, is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307450
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  • 107
    Electronic Resource
    Electronic Resource
    The effect of chlorpromazine and tetracaine on the rapid axonal transport of neurosecretory material in the hypothalamo-neurohypophysial system of the rat (1973)
    Springer
    Cell & tissue research 143 (1973), S. 71-91 
    Details
    ISSN: 1432-0878
    Keywords: Axonal transport ; Neurosecretion ; Posterior pituitary ; Anesthetics ; Chlorpromazine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of chlorpromazine (cpz) and tetracaine (tc) on the rapid axonal transport of neurosecretory material (NSM) in the hypothalamo-neurohypophysial system was investigated. Following subarachnoidal injection of these drugs, the incorporation of (35S) cysteine into proteins of the supraoptic nucleus was slightly depressed. The protein-bound radioactivity in the posterior pituitary was markedly lowered in experimental rats which indicates a partial blockage of the rapid axonal transport of NSM along the hypothalamoneurohypophysial tract. Both cpz and tc induced an increase in the number of mitochondria and profiles of granular endoplasmic reticulum. The axons in the infundibulum and neurohypophysis were enlarged by dammed organelles, indicating a blockage of axonal transport. There was an increased number of microvesicles, often arranged in a crystalloid pattern, in the terminals. The number and distribution of neurotubuli and neurofilaments were not changed. A possible stimulatory effect of cpz on the release of NSM from the neural lobe is assumed Possible mechanisms for the action of mitotic inhibitors, transquilizers and local anesthetics are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307452
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  • 108
    Electronic Resource
    Electronic Resource
    Haemocyanin production in pore cells of the freshwater snail Lymnaea stagnalis (1973)
    Springer
    Cell & tissue research 145 (1973), S. 443-445 
    Details
    ISSN: 1432-0878
    Keywords: Haemocyanin ; Pore cells ; Lymnaea stagnalis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron micrographs of pore cells of Lymnaea stagnalis suggest that these cells produce and store haemocyanin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307166
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  • 109
    Electronic Resource
    Electronic Resource
    Fine structure and innervation of the avian adrenal gland (1973)
    Springer
    Cell & tissue research 145 (1973), S. 417-442 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal chromaffin cells ; Birds ; Cholinergic innervation ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary According to their ultrastructure and histochemistry three types of efferent nerve fibers can be distinguished in the bird's adrenal gland. The main part is made up of cholinergic fibers recognizable by a positive reaction for acetylcholinesterase and two specific populations of granules within the synaptic ending. Synaptic vesicles measuring 300 to 500 Å in diameter and dense-cored vesicles with a diameter of about 1 000 Å are discernible. In the periphery of the gland cholinergic axons for the innervation of adrenal cells form large bundles surrounded by a perineural sheath. The bundles cross the capsule and are situated within the adrenal chromaffin cords or at their periphery. Finally small groups of fibers enter a group of chromaffin cells which are surrounded by a basal lamina and which consist of about a dozen or more cells producing adrenaline and noradrenaline. Synaptic endings occur, above all in passeriform species, in the center of a chromaffin cell complex. They are either attached to the innervated cells or their dendrite-like processes, or embedded into the cells, or connected to short spines of the innervated cells. Synaptic and dense-cored vesicles leave the bouton by exocytosis. One synaptic terminal may innervate up to three A- or NA-cells. The existence of different types of synapses for A- and NA-cells cannot be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307165
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  • 110
    Electronic Resource
    Electronic Resource
    Ultrastructure of motor nerve terminals on different types of muscle fibers in the atlantic hagfish (Myxine glutinosa, L.) (1973)
    Springer
    Cell & tissue research 147 (1973), S. 87-105 
    Details
    ISSN: 1432-0878
    Keywords: Motor nerve terminals ; Myxine glutinosa (L.) ; Elongated vesicle profiles ; Dense-core vesicles ; Fixation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary “White” and “intermediate” parietal muscle fibers of Myxine are innervated focally at one end. Most synaptic vesicles are “empty”. These terminals also contain 1–2% large 800–1.100 Å dense-core vesicles. “Red” fibers of parietal and craniovelar muscle are innervated in a distributed fashion, and the presynaptic profiles contain a higher number of large dense-core vesicles (averaging 9% and 15%, respectively; up to 37%). For all terminals the synaptic gap is 450–600 Å wide, and postsynaptic folds are absent. “Empty” synaptic vesicles exist as round or elongated profiles. The proportion of elongated profiles increases by formation from round ones when increasing the molarity of the buffer in the aldehyde fixative. Furthermore, the proportion of elongated vesicle profiles in terminals on Myxine “white” fibers at different buffer molarities, is identical with that in mammalian motor terminals at similar molarities. On this basis the significance and mode of formation of elongated vesicle profiles is discussed. The conclusion is made that the susceptibility of “flattening” depends on the osmotic pressure of the vesicle contents once the aldehyde has influenced the vesicle membrane. The different vesicle populations in terminals on different types of muscle fibers are significant. Terminals on “red” fibers probably contain serotonin (5-HT) either as sole transmitter or in addition to acetylcholine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306602
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  • 111
    Electronic Resource
    Electronic Resource
    Nucleolus-like inclusions in neuronal perikarya and processes: Phase and electron microscope observations on the hypothalamus of the mouse (1973)
    Springer
    Cell & tissue research 146 (1973), S. 329-337 
    Details
    ISSN: 1432-0878
    Keywords: Ventromedial hypothalamic nuclei ; Nucleolus-like cytoplasmic inclusions ; Albino mouse ; Phase microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die ventromedialen Hypothalamuskerne von Mäusen nach Goldthioglucose-Injektion und von Kontrollmäusen wurden phasenoptisch und elektronen-mikroskopisch untersucht. Die neuronalen Perikaryen und Fortsätze enthielten nucleolusähnliche, phasenkontrast- und elektronenmikroskopisch sichtbare Einschlußkörper. Diese bestanden aus rundlichen, nicht membranbegrenzten Anhäufungen eines granulär oder filamentär erscheinenden Materials von unterschiedlicher Dichte. Gelegentlich wurden auch längliche Formen beobachtet. Sogar in stark geschädigten Nervenzellen waren die Einschlüsse noch als relativ gut erhaltene Strukturen zu erkennen. Es wird die Hypothese aufgestellt, daβ die nucleolusähnlichen Körper eine Depot- oder Transitform von schnell verfügbarem Material darstellen, welches entweder in den Perikaryen angehäuft oder in den Fortsätzen zum Ort der Verwendung und/oder Freisetzung transportiert wird.
    Notes: Summary The ventromedial hypothalamic nuclei of goldthioglucose-treated and control mice were examined by phase and electron microscopy. Neuronal perikarya and processes contained nucleolus-resembling inclusion bodies detectable by phase and electron microscopy. The inclusions consisted of round unbounded masses of granular- or filamentous-appearing material of variable density. Elongated forms were occasionally seen. Even in damaged nerve cell bodies and processes the inclusions were recognizable as relatively well-preserved structures. The hypothesis is presented that they represent a storage or transit form of readily available material which is either piled up in the perikaryon or moved along its processes before being finally used and/or released.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02346225
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  • 112
    Electronic Resource
    Electronic Resource
    Fine structure and innervation of the avian adrenal gland (1973)
    Springer
    Cell & tissue research 146 (1973), S. 403-416 
    Details
    ISSN: 1432-0878
    Keywords: Avian interrenal gland ; Cholinergic innervation ; P-type nerve fibers ; Adrenergic terminals ; 6-OHDA ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In all bird species investigated interrenal cells are reached by cholinergic nerve fibers forming synapses without postsynaptic membrane thickenings at their basis, more rarely at the lateral or apical cell surfaces. The density of innervation is considerably low if compared to the adrenal chromaffin organ; it is about 3 mm nerve length per 1 mm3 interrenal tissue in the house sparrow, 5 in the domestic fowl and 8 inCorvus frugilegus. P-type fibers which are only rarely to be seen also penetrate the basal lamina surrounding interrenal cells. Adrenergic fibers are only found outside the basal lamina.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02346231
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  • 113
    Electronic Resource
    Electronic Resource
    The structure of the salivary gland of the moth (Manduca sexta) (1973)
    Springer
    Cell & tissue research 146 (1973), S. 553-564 
    Details
    ISSN: 1432-0878
    Keywords: Salivary gland Moth ; Protein secretion ; Fluid secretion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The salivary glands of the moth,Manduca sexta, are described, emphasizing correlations between structure and function in an attempt to explain the production of a dilute saliva. Each of the paired glands consists of five distinct regions: protein secreting, fluid secreting, thin duct, bulbous duct, and common duct. Each region constists of a single, ultrastructurally distinct, cell type. It is proposed that the protein and fluid secreting regions produce an enzyme-containing primary saliva isosmotic with the haemolymph; this saliva is modified in the remaining regions of the gland to yield a dilute saliva.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02347183
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  • 114
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in the coronet cells of the saccus vasculosus from rainbow trout, Salmo gairdneri (Richardson), kept in sea water (1973)
    Springer
    Cell & tissue research 139 (1973), S. 271-284 
    Details
    ISSN: 1432-0878
    Keywords: Saccus vasculosus ; Rainbow trout ; Coronet cell ; Sea water adaptation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The coronet cells of saccus vasculosus of fresh-water living and sea-water adapted rainbow trout were studied with the electron microscope, with special regard to changes in the latter group. Only quantitative differences were observed, namely a raised number of mitochondria in the apical region and the head and also a concentration of the agranular endoplasmic reticulum with a higher amount of electron-dense material and vesicles around the Golgi saccules. Together, these findings suggest a secretory function for the coronet cell. A supposed transport of vesicles from the head region of the coronet cell out into the globules is suggested. Interrelation between primary and secondary vesicles is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306526
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  • 115
    Electronic Resource
    Electronic Resource
    Elektronenmikroskopische und histochemische Untersuchungen zur Funktion der Branchialdrüse (Parabranchialdrüse) der Cephalopoda (1973)
    Springer
    Cell & tissue research 139 (1973), S. 253-269 
    Details
    ISSN: 1432-0878
    Keywords: Branchial gland ; Cephalopoda ; Fine structure ; Hemocyanin ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Licht- und elektronenmikroskopische Untersuchungen an der Branchialdrüse verschiedener Cephalopoden (Sepia officinalis, Octopus vulgaris, Loligo vulgaris, Eledone moschata) zeigen, daß das Drüsengewebe des stark vaskularisierten Organs aus einem sekretorisch aktiven Zelltypus mit ausgeprägtem endoplasmatischen Retikulum besteht. In den Zisternen des endoplasmatischen Retikulums lassen sich granuläre und ringförmige Strukturen (Durchmesser: 45–65 Å und 170 Å) nachweisen, die in Größe und Gestalt mit den Hämocyanin-Einheiten in den Gefäßen und Lakunen übereinstimmen und durch randlichen Zerfall der Zellen in den Blutraum auszuwandern scheinen. Die histochemischen Untersuchungen ergeben eine positive Reaktion für Monoaminoxydase, aber vergleichsweise geringe Phosphatase- und Dehydrogenase-Aktivitäten. Diese Befunde sowie der histochemisch nachgewiesene hohe Kupfergehalt des Drüsengewebes sprechen für eine hämopoetische, d.h. hämocyaninbildende Funktion der Kiemendrüse.
    Notes: Summary Light and electron microscopic investigations on the branchial gland of different Cephalopoda (Sepia officinalis, Octopus vulgaris, Loligo vulgaris, Eledone moschata) show that the gland tissue, strongly vascularized, consists of an actively secreting cell type with a remarkable endoplasmatic reticulum. In the cisternae of the endoplasmatic reticulum granular and ring-shaped structures can be identified (diameter: 45–65 Å and 170 Å) which correspond in size and shape with the hemocyanin units in the vessels and lacunae and which seem to emigrate into the blood space caused by the peripheral decay of the cells. Histochemical investigations show a positive reaction for monoaminoxidase, but comparatively low phosphatase and dehydrogenase activities. These results, and also the high content of histochemically identified copper in the gland tissue, seem to indicate a hemopoetic, i.e. hemocyanin-forming function for the branchial gland.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306525
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  • 116
    Electronic Resource
    Electronic Resource
    Evolution des glandes prothoraciques de larves permanentes de Locusta migratoria obtenues par irradiation sélective du tissu hématopoïétique (1973)
    Springer
    Cell & tissue research 137 (1973), S. 387-397 
    Details
    ISSN: 1432-0878
    Keywords: Insect molting ; Hemocytopoietic tissue ; Prothoracic glands ; Irradiation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It has been shown in previous studies that the endocrine control of molting is blocked by selective X-irradiation of the hemocytopoietic tissue of young last instar larvae of Locusta migratoria, the treated animals surviving as larvae for months without ever initiating a molt. The aim of the present study is to determine, on both a morphological and a physiological basis, if the block is related to a precocious functional involution of the prothoracic glands, known to elaborate a molting hormone. The prothoracic glands of normal animals clearly show morphological signs of functional involution during the late fifth (last) larval instar and degenerate completely some days after the imaginal molt. In the prothoracic glands of X-ray treated animals (selective irradiation of the hemocytopoietic tissue, the prothoracic glands being shielded), the signs of intense secretory activity persist up to 40 days following the irradiation. No signs of involution could ever be noticed in the prothoracic glands of such larvae. The irradiation of the hemocytopoietic tissue thus not only blocks molting, but also prevents the normal involution of the prothoracic glands. Extirpation of the prothoracic glands in young larvae of Locusta is known to result in the inhibition of the subsequent molt. Implantation of prothoracic glands from normal donors of the same age restores molting in fifth instar larvae previously deprived of their own glands. Using these results in physiological assays for the implanted prothoracic glands, we chose as donors irradiated animals of different ages and young normally developing adults. The prothoracic glands of irradiated animals fully retain their physiological activity after the X-ray treatment and are able to induce molting in larvae deprived of their own glands. It appears that the radiosensitive cells of the hemocytopoietic tissue of Locusta produce a substance which, while having no overt influence on the functioning of the prothoracic glands, is necessary for molting and probably acts in synergy with the prothoracic factor (molting hormone).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307211
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  • 117
    Electronic Resource
    Electronic Resource
    Germ cell degeneration and intercellular bridges in the human fetal ovary (1973)
    Springer
    Cell & tissue research 138 (1973), S. 23-30 
    Details
    ISSN: 1432-0878
    Keywords: Germ cell ; Human degeneration ; Intercellular bridges ; Oogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intercellular bridges between developing germ cells were observed in human fetal ovaries at 10 to 20 weeks gestation. Bridges were frequently found between cells in early stages of degeneration, with similar regressive changes being present in the conjoined cells. In advanced stages of cellular degeneration, bridges were less frequently found and were generally distorted and partially disrupted. Similarity in appearance of adjacent degenerating cells was common, even in late stages of degeneration. These observations suggest that cellular interconnection may be responsible for synchronous degeneration of germ cells during oogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307075
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  • 118
    Electronic Resource
    Electronic Resource
    The fine structure of the pancreatic nerves of the domestic fowl (1973)
    Springer
    Cell & tissue research 136 (1973), S. 501-510 
    Details
    ISSN: 1432-0878
    Keywords: Pancreas ; Fowl ; Innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the pancreatic nerves of the domestic fowl has been studied. Naked axon beadings were found in membranous contact with endocrine as well as exocrine cells. From an anatomical point of view it seems reasonable to suggest that the endocrine glands might be subjected to some influence of the autonomic nervous system.
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    URL: http://dx.doi.org/10.1007/BF00307366
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    Unique sensory endings in rat muscle spindles (1973)
    Springer
    Cell & tissue research 136 (1973), S. 511-520 
    Details
    ISSN: 1432-0878
    Keywords: Muscle spindle ; Sensory ending ; Rat ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A fine structural study of sternothyroid muscle spindles of young adult rat demonstrates the rare occurrence of unique nerve endings. These endings are situated in the juxta-equatorial region of nuclear-bag fibers, adjacent to the annulo-spiral sensory endings. They consist of a bundle of terminal axons less than 0.3 μ in diameter and appear to be disposed nearly longitudinally to the axis of the intrafusal fibers. Whereas, the annulo-spiral endings consist of a single axon, coiling around the intrafusal fibers. Transverse sections of these muscle spindles reveal these unique endings scattered around the muscle fibers, fitting into depressions on their surface. The innermost axons directly face the muscle surface and are separated by a narrow gap less than 200 Å in width. No Schwann cell process appears to be associated with these endings. From their unique multi-axonal composition, these endings are termed “bundled endings”. Investigations of developing muscle spindles show the occasional presence of a similar multi-axonal composition of sensory endings in perinatal rats. It is suggested that “bundled endings” are sensory in nature, carrying an immature feature over to adult life.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307367
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  • 120
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    Lymphoid stem cell identification in the developing thymus and bursa of fabricius of the chick (1973)
    Springer
    Cell & tissue research 136 (1973), S. 521-533 
    Details
    ISSN: 1432-0878
    Keywords: Thymus ; Bursa of Fabricius ; Chick embryo ; Lymphoid precursor cell, Lymphoid cell homing ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Lymphoid precursor cell structure in the earliest stages of lymphoid development of the chick thymus and bursa of Fabricius was investigated light- and electron microscopically. The first lymphoid precursor cells around (8 days' incubation) and within (9 days') the epithelial thymus show the morphological features of motile cells, viz. pseudopodia and cytoplasmic bundles of filaments. Subsequent differentiation into lymphoid cells includes disappearance of pseudopodia and filaments, and appearance of a layer of marginal condensed heterochromatin in the nuclei. The first lymphoid precursor cells in the bursa mesenchyme (11 days' incubation) and bursa epithelial bud (12 days') are also characterized as motile cells; the intra-vascular lymphoid cells (13 days') of the bursa, though resembling the lymphoid cells in other localizations, lack their irregular cytoplasmic contours. The motile lymphoid cells in the early stages of lymphoid development of the chick thymus and bursa are not identical, but are distinguished by their cytoplasmic and nuclear organization: endoplasmic reticulum profiles and marginal heterochromatin, present in lymphoid cells of the bursa, are absent in those of the thymus. These and other data suggest that thymus and bursa lymphoid cells originate in different haemopoietic organs, those of the thymus in the yolk sac and those of the bursa in the spleen.
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    URL: http://dx.doi.org/10.1007/BF00307368
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    The fine structure of the branchial heart appendage of the cephalopod Octopus dofleini martini (1973)
    Springer
    Cell & tissue research 136 (1973), S. 545-568 
    Details
    ISSN: 1432-0878
    Keywords: Pericardial gland ; Octopus ; Excretory organ ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The branchial heart appendage of Octopus dofleini martini has been investigated electron microscopically. This organ is dominated by peripherally lobed blood sinuses. It contains free hemocyanin (often aligned in rows), amoebocytes, endothelial cells, and muscle cells which occur mainly in connection with neurons. The neurons are often exposed to the blood. The blood sinuses are enclosed by a basement membrane which contains collagen equivalents and fine fibrillar elements. The sinuses are covered by two different epithelia: 1) the epithelium in the caoity of the appendage consisting of irregularly shaped cells with processes, the so called (∼ 30 μ high) podocytes, and 2) the epithelium (∼ 40 μ in height) on the surface of the organ, which is composed of two parts: a) a “lacuna”-forming portion directly adjacent to the basement membrane, which is topped by b) a continuous tissue portion with occasional “lacuna”-canals. The intercellular spaces of the inner and outer epithelium are connected. The structures of these epithelial cells are discussed in relation to the formation of the pericardial fluid.
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    URL: http://dx.doi.org/10.1007/BF00307370
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  • 122
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    Annular nucleolus in Leydig cells of mouse (1973)
    Springer
    Cell & tissue research 137 (1973), S. 167-175 
    Details
    ISSN: 1432-0878
    Keywords: Leydig cells ; Mouse ; Ring-shaped nucleolus ; Endoplasmic reticulum ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Many mature Leydig cells of adult mice contain annular nucleoli. In the cytoplasm of these cells, there is an abundance of agranular endoplasmic reticulum and its modifications, i.e. membranous whorls and double-walled tubules. By contrast, the cytoplasm of Leydig cells with compact nucleoli shows abundant free ribosomes and granular endoplasmic reticulum. It is assumed that the granular endoplasmic reticulum shifts to the agranular endoplasmic reticulum and its modifications during the differentiation of the Leydig cell. For the maturation of the Leydig cell the annular nucleoli may play an important role.
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    URL: http://dx.doi.org/10.1007/BF00307428
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    Ultrastructural observations on membranous structures in developing mouse oocytes (1973)
    Springer
    Cell & tissue research 137 (1973), S. 159-166 
    Details
    ISSN: 1432-0878
    Keywords: Ovum ; Mouse ; Membranes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural studies have revealed the presence of unusual membrane complexes within developing mouse oocytes. These structures, most obvious 18 days post fertilization, are found in the nucleus or cytoplasm of cells in meiotic prophase. The complexes, usually found in small groups, are characterized by a slightly bowed appearance, and a thin middle section that is vesiculated at each end. At high magnification the middle section exhibits a pentalaminar structure similar to tight junctional complexes, while the looped membranes of the vesiculated ends are trilaminar in appearance. In addition to being free in the nucleoplasm or cytoplasm, the complexes are also seen in continuity with the inner and outer leaflets of the nuclear envelope, and with typical membranes forming cytoplasmic tubular systems. The possible formation of these complexes from blebs or vesicles derived from the nuclear envelope is presented and the role that these structures may play in developing oocytes is discussed.
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    URL: http://dx.doi.org/10.1007/BF00307427
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    Electron microscopic study on the thyroid gland of the salamander Hynobius nebulosus in the breeding season (1973)
    Springer
    Cell & tissue research 137 (1973), S. 195-208 
    Details
    ISSN: 1432-0878
    Keywords: Thyroid (Salamander) ; Influence of TSH ; Epithelial cells ; Crystalloid structures ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of thyrotropic hormone (TSH) on the salamander thyroid gland was studied by electron microscopy. The following sequence of changes in the follicular cells was observed: (1) 1–1.5 hrs after a single administration of 1 i.u. of TSH, many large colloid droplets appear in the apical cytoplasm; (2) within about 2 hrs hereafter, most of them are replaced by large vacuolar bodies, and cytosomes are remarkably decreased; (3) 2.5–3 hrs after two administrations of 1 i.u. of TSH at an interval of 20 hrs, large vacuolar bodies with or without filaments are frequently observed but cytosomes are hardly encountered; (4) in the group placed at room temperature for 10 days after a single administration of TSH, large vacuolar bodies almost disappear; (5) in the group placed in the ice room for 10 days after the same treatment, large vacuolar bodies with or without filaments frequently appear but cytosomes almost disappear; and (6) in some of large vacuolar bodies with filaments the different stages of crystalloid formation are discernible. From these findings, it is suggested that large colloid droplets are changed into large vacuolar bodies and that crystalloid originates from large vacuolar bodies with filaments, probably as a result of interrupted hydrolysis caused by a deficiency of cytosomes.
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    URL: http://dx.doi.org/10.1007/BF00307430
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    The ultrastructure of the pars distalis of the hypophysis in males of Triturus cristatus carnifex Laur., treated with the antiandrogen cyproterone acetate (1973)
    Springer
    Cell & tissue research 137 (1973), S. 209-221 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Male ; Triturus cristatus carnifex Laur. ; “Globular basophil cells” ; Antiandrogen treatment ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adenohypophysis of the newt Triturus cristatus carnifex Laur. shows three types of cells: 1) cells with granules of about 350–550 mμ in diameter, 2) cells with small granules of 200–250 mμ in diameter and globules with a cristal-like arrangement containing cylinders with a diameter of about 960 Å and 3) cells containing small granules only. The AA. discuss the ultrastructural changes of the gland and the modifications of sexual secondary characters (S.S.C.) in animals given Cyproterone acetate (1/2 mg every three days). The animals have been treated for a period of time varying between 3 and 5 months, starting in October-November, when S.S.C. begin to develop again. At the end of the treatment the newths showed a loss of S.S.C., and the ultrastructure of the adenohypophysis resembled that of castrated animals, i.e.: great swelling of R.E.R. and partial degranulation of glycoprotein secreting cells which contain the 200 mμ granules and the globules. The S.E.R. showed also swelling and hyperactivity.
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    URL: http://dx.doi.org/10.1007/BF00307431
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    A quantitative electron microscopic analysis of myelination in the optic nerve of suckling rats treated with an inhibitor of cholesterol biosynthesis (1973)
    Springer
    Cell & tissue research 140 (1973), S. 9-23 
    Details
    ISSN: 1432-0878
    Keywords: Optic nerve ; Myelination ; Hypocholesteremic drug ; Exogenous and endogenous cholesterol ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of AY-9944, an inhibitory cholesterol biosynthesis, on the myelination of the optic nerve of rats was studied. Suckling rats were injected intraperitoneally with the drug every other day from birth, and were sacrificed at 10, 20 and 30 days of age together with littermate controls. The analysis is based on counting, at the electron-microscope level, the number of unmyelinated axons and the number of myelin lamellae surrounding each myelinating axon. The results indicate that a decrease in endogenous cholesterol by AY 9944, induced an overall retardation of the myelination process in the optic nerve: a larger proportion of myelinated axons and smaller number of myelin lamellae around the myelinating axons, when compared with the littermate controls, was observed. Exogenous cholesterol from the maternal milk did not compensate for a lack in endogenous cholesterol. Degenerating myelin sheaths were frequently seen in the experimental optic nerves at 20 and 30 days of age. Numerous membranous, intracytoplasmic drug-induced inclusions were found at all ages studied.
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    URL: http://dx.doi.org/10.1007/BF00307056
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    Ultrastructural study on contractile structures in mammalian nephron (1973)
    Springer
    Cell & tissue research 140 (1973), S. 101-124 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Contractile structures ; Embryonic metanephros ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytoplasmic filaments have been observed in the cells of normal and pathological kidneys. These filaments are usually grouped into bundles anchored to electron dense bodies underlying the cell membrane. In the embryonic human metanephros the filaments are found within the cells of different portions of the nephron at various stages of development. They appear first in the podocytes, almost simultaneously in the Bowman's capsule and tubular cells, then in the “mesangial cells”, and finally in the cells of the media of the afferent glomerular and interlobular arterioles. The presence of filaments and their attachment bodies in the mammalian nephron suggests that the podocytes and the so-called mesangial cells have a contractile activity, thus representing an intraglomerular apparatus which regulates the intravascular pressure, blood flow and filtration rate in the glomerular capillaries, whilst the contractile activity of the Bowman's capsule and proximal, distal, and collecting tubules, could facilitate the progression of the filtrate. The increase in number of the filaments in some pathological conditions is probably related to the functional changes of the intraluminal pressure in the glomerular capillaries, in the Bowman's space, and in the tubular lumen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307061
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    Ultrastructure de l'organe de Johnston de la Fourmi Camponotus vagus Scop. (Hymenoptera, Formicidae) (1973)
    Springer
    Cell & tissue research 140 (1973), S. 39-75 
    Details
    ISSN: 1432-0878
    Keywords: Johnston's organ ; Camponotus vagus (Hymenoptera, Formicidae) ; Chordotonal structure, Scolopidia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'organe de Johnston de Camponotus vagus est composé par un ensemble d'environ 55 structures chordotonales, chacune étant formée par une ou plusieurs scolopidies. Les terminaisons dendritiques de tous les organes chordotonaux aboutissent sous des cônes cuticulaires insérés dans la membrane d'articulation entre le pédicelle et le troisième article antennaire. Chaque scolopidie est composée de 3 dendrites; les trois segments proximaux sont entourés par une même cellule enveloppe CE1 fortement accolée aux cellules épithéliales adjacentes au moyen d'attaches spécifiques. Au niveau des racines ciliaires et des segments ciliaires les trois dendrites sont enveloppés dans une cellule scolopale qui sécrète des colonnes scolopales autour de chaque dendrite et ayant des points de jonctions avec ceux-ci. Ces colonnes scolopales se réunissent ensuite pour entourer les trois dendrites dans un cylindre scolopal unique. A partir des dilatations ciliaires les dendrites évoluent de façon différente; certains s'interrompent très tôt dans le cylindre scolopal alors que d'autres s'élèvent plus haut jusqu'à l'articulation, leur extrémité distale étant coiffée d'un tube cuticulaire. Par structure chordotonale il n'y a généralement qu'un dendrite — quel que soit le nombre des scolopidies à l'origine de la structure — qui est relié à la membrane articulaire par une «tigelle cuticulaire intermédiaire». Chaque structure chordotonale est formée par une scolopidie, ou le regroupement de plusieurs identiques à celle décrite ci-dessus. Le plus souvent les premières cellules enveloppes CE1 présentent des zones d'affrontement membranaires entre CE1 des scolopidies d'un même organe chrodotonal. A partir du niveau des cellules scolopales, deux cellules enveloppes CE2 et CE3, se relayent successivement, formant un manchon autour des groupements scolopidiaux, déterminant ainsi l'unité sensorielle. On a observé et décrit des différenciations intercellulaires à tous les niveaux du système, entre éléments nerveux d'une part et éléments nerveux et structures associées d'autre part. Des inclusions particulières telles des microtubules associées en chaîne au moyen de bras ont notamment été décrites au niveau de structures de jonctions. Le rôle des divers structures et caractères spécifiques rencontrés lors de la description de l'ensemble de la structure réceptrice est envisagé dans le sens des mécanismes de transduction.
    Notes: Summary Johnston's organ of Camponotus vagus is composed of 55 chordotonal structures, each of them being formed by one or several scolopidia. The dendritic endings of the chordotonal organs are in contact with cuticular cones which occur at the articular joint between pedicellus and the third antennal segment. Each scolopidium is composed of three dendrites. The three proximal segments are enclosed by one cell, CE1, which is connected with neighbouring epithelial cells by specific attachment zones containing microtubules. At the level of the ciliary roots and of the dendritic ciliary segments, the three dendrites are enclosed by the scolopal cell which secretes the scolopal rod around each dendrite. Some junctions occur between the dendrites and the scolopal cell. The scolopal rods are interconnected constituting the scolopal ring. The distal portion of each dendrite exhibits a different ultrastructure: some of them are short and terminate in the scolopal ring while others continue to the joint, here being covered by a cuticular canal. Generally there is only one dendrite which is connected with the joint by a cuticular stalk. Each chordotonal structure is formed by one or several scolopidia. Very often the first ensheathing cells, CE1, of one organ are connected by some intercellular differentiations. Above the scolopal cells two other ensheathing cells, CE2 and CE3 are to be found. These cells define each sensory unit. Intercellular differentiations are described at all levels of the system, between neural elements on the one hand and between neural elements and associated structures on the other hand. Specific inclusions such as associated “arm-bearing” microtubules are described near some of the junctions. The possible role of these specific structures in the process of impulse conduction in mechanoreceptors is discussed. The results are compared with those obtained from Johnston's organs of other species. Their functional significance is discussed.
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    URL: http://dx.doi.org/10.1007/BF00307058
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    Ultrastructural studies of spermatogenesis in Drosophila melanogaster meigen (1973)
    Springer
    Cell & tissue research 140 (1973), S. 125-144 
    Details
    ISSN: 1432-0878
    Keywords: Spermatogenesis ; Meiosis ; Drosophila melanogaster ; Synaptinemal complex ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Meiosis in male Drosophila melanogaster was studied with the electron microscope. The number and the distribution of ring channels between individual members of a cluster of primary spermatocytes was determined from serial sections. The tubules with a diameter of 45 nm characteristic for meiotic prophase nuclei gave a chromatin type reaction, when treated with EDTA according to Bernhard's technique, thus suggesting that these tubules contain DNA. A material resembling central regions of synaptinemal complexes was observed in the nucleolus of primary spermatocytes during the downward movement in the testis. It is suggested that they represent unused precursors to central components of synaptinemal complexes, which are absent at pachytene of Drosophila males. Up to six tail fibers (kinetosomes + axonemes) were observed in every primary spermatocyte prior to meiosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307062
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    The development of synapses in vitro between previously dissociated chick spinal cord neurons (1973)
    Springer
    Cell & tissue research 140 (1973), S. 203-216 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Development ; Chick embryo ; Cell culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The formation and development of synaptic contacts between dissociated chick spinal cord neurons has been investigated. By the 6th day in vitro “immature” profiles with few vesicles were observed. By 14–18 days “mature” types with numerous vesicles were found, indistinguishable from those of newly hatched chick spinal cord. After this period degeneration occurred, and was especially marked in the post-synaptic element. Such degeneration could be postponed by the addition of small numbers of somatic muscle cells. The Kanaseki and Kadota (1969) technique was applied to the study of coated vesicles at various stages of synaptic development.
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    URL: http://dx.doi.org/10.1007/BF00306695
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    Quantitative microscopical studies of the mouse peritoneal macrophage following stimulation in vivo (1973)
    Springer
    Cell & tissue research 140 (1973), S. 187-202 
    Details
    ISSN: 1432-0878
    Keywords: Macrophage ; Differentiation ; Triolein ; Stereology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The results of an objective two- and three-dimensional analysis of the morphological features of normal and triolein-induced mouse peritoneal macrophages are reported. An “equivalent circle“ technique for resolving the effects of volume and surface area on volume-to-surface parameters is described. The method is a simple comparative one which does not require the actual determination of cell volume. Macrophage stimulation promoted increases in mean cell size, cytoplasmic granularity and volume-to-surface ratio. In addition, a reduction in nuclear volume-to-surface ratio accompanied in vivo stimulation. Nucleocytoplasmic ratio remained constant. The equivalent circle procedure showed that the increase in cellular volume-to-surface ratio was due largely to the increase in cell volume; the decrease in nuclear volume-to-surface ratio was primarily the result of a substantial increase in nuclear membrane surface area. Stereological estimations suggest that interiorized cell membrane (in the form of triolein-containing phagosomes) is replaced by newly reconstructed surface membrane.
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    URL: http://dx.doi.org/10.1007/BF00306694
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    Cytologische Studien an Trichocysten (1973)
    Springer
    Cell & tissue research 140 (1973), S. 235-259 
    Details
    ISSN: 1432-0878
    Keywords: Ciliated protozoa ; Loxophyllum and Prorodon ; Trichocysts ; Toxicysts ; Expulsion mechanism ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Nesselkapseltrichocysten der Ciliaten Loxophyllum und Prorodon wurden hinsichtlich ihrer Feinstruktur sowie des Ausschleuderungsablaufes untersucht. Loxophyllum besitzt zwei morphologisch unterscheidbare Sorten von Toxicysten, wohingegen Prorodon nur eine Art dieser Organelle aufweist (Krüger, 1936). Wie an Hand gehemmter Stadien gezeigt werden kann, verläuft die Ausschleuderung bis auf geringfügige Variationen bei den drei Sorten in der gleichen Art: Schläuche, die im ruhenden Zustand bereits in den endgültigen Dimensionen in der Toxicystenkapsel eng ineinandergeschachtelt vorliegen, werden handschuhfingerförmig umgestülpt und verlassen hierdurch die Kapsel und damit den Zellkörper. Dieser Prozeß ist mit der Ausscheidung einer teils fädigen, teils amorphen Substanz gekoppelt. Der Umstülpungsvorgang der Innenstruktur der Nesselkapseltrichocysten wird mit den völlig andersartigen, während der Ausschleuderung von Mucocysten und Spindeltrichocysten ablaufenden morphologischen Veränderungen verglichen. Es zeigte sich, daß aufgrund ihrer differierenden Feinstrukturen und Funktionsweisen in den Nesselkapseltrichocysten einerseits und in den Mucocysten sowie Spindeltrichocysten andererseits zwei grundsätzlich voneinander verschiedene Organellentypen gesehen werden müssen.
    Notes: Summary The toxicysts of the ciliates Loxophyllum meleagris and Prorodon teres were examined with regard to fine structure and expulsion mechanism. Loxophyllum possesses two morphologically distinct types of toxicysts, whereas in Prorodon only one type is present. As can be shown by discharge inhibition experiments, the expulsion mechanisms, except for small variations, are identical in all three types: Tubes, which in their resting state lie closely packed one within the other possess already at this state their final dimensions; they are inverted, thereby leaving the capsule and thus the cell body. This process is correlated with the excretion of a substance partly filamentous, partly amorphous. The inversion of the tubes during the expulsion is compared to the fundamentally different morphological alterations during discharge of mucocysts and spindle trichocysts. The differences and similarities in fine structure and function between toxicysts on the one hand and mucocysts and spindle trichocysts on the other, indicate that two rather than three fundamentally different organelle types must be distinguished.
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    URL: http://dx.doi.org/10.1007/BF00306697
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    Ultrastructural changes in the superficial layers of the superior colliculus in Galago crassicaudatus (primates) after eye enucleation (1973)
    Springer
    Cell & tissue research 140 (1973), S. 291-307 
    Details
    ISSN: 1432-0878
    Keywords: Superior colliculus ; Primate, Galago ; Optic terminals ; Eye enucleation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Several types of terminals were found in the three superficial collicular layers of Galago. At least two axon terminals with round vesicles (R1 and R2) could be distinguished on the basis of vesicle packing and electron density of the cytoplasmic and mitochondrial matrices. R1 axon terminals were characterized by aggregations of vesicles in an electron lucent cytoplasm and mitochondria with a relatively dark matrix, while in R2 axon terminals the vesicles were more evenly distributed in an electron dense cytoplasm and the mitochondrial matrix was pale. R2 endings occurred in clusters in the stratum griseum superficiale; they were absent in the stratum zonale. R1 endings were found in all three superficial collicular layers. Both types of R terminals made asymmetrical contacts with small dendrites, dendritic spines and F profiles. Profiles containing flattened vesicles and establishing symmetrical contacts were numerous, and many could be identified as dendrites by accepting as criteria for dendrites evenly spaced microtubules, clusters of ribosomes and the fact that these F profiles were postsynaptic to other terminals. F terminals were presynaptic to other F profiles, dendrites and somata; they were postsynaptic to R terminals and took part in serial synapses. Dendrodendritic contacts were frequent, somatodendritic contacts rare. After eye enucleation most R2 axon terminals underwent the electron dense degenerative reaction. The degeneration process was a lengthy one; many degenerating boutons were found 30 days after axotomy and some persisted up to 180 days postoperatively. There was strong indication that the superior colliculus received more crossed than uncrossed retinofugal fibers. The crossed and uncrossed retinocollicular axons terminated in two different substrata of the stratum griseum superficiale.
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    URL: http://dx.doi.org/10.1007/BF00307019
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    The fine structure of the guinea-pig muscle spindle (1973)
    Springer
    Cell & tissue research 140 (1973), S. 357-368 
    Details
    ISSN: 1432-0878
    Keywords: Muscle spindle ; Guinea-pig ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nuclear bag and nuclear chain intrafusal fibres are present in guinea-pig muscle spindles. Unlike muscle spindles in other species two types of nuclear chain fibre seem to be present. The electron microscopical appearance of one type of nuclear chain fibre is similar to that of nuclear bag fibres. It is suggested that under tension the nuclei of small nuclear bag fibres become sufficiently displaced to form nuclear chain-like fibres. The frequent occurrence of fibres which combine some of the properties of both nuclear bag and nuclear chain fibres indicates the possible occurrence of a third type of intrafusal fibre. The sensory innervation of guinea-pig muscle spindles is similar to that of the cat and the rat. Three types of motor nerve ending which could be classified according to the complexity of their subneural apparatus were seen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307023
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  • 135
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    Evidence for the existence of serotonin-, dopamine-, and noradrenaline-containing neurons in the gut of Lampetra fluviatilis (1973)
    Springer
    Cell & tissue research 141 (1973), S. 33-54 
    Details
    ISSN: 1432-0878
    Keywords: Intestine, Lampetra fluviatilis ; Serotonin-, dopamine-, noradrenaline-containing neurons ; Identification by histochemistry ; Electron microscopy ; Biochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Monoamine-containing neurons in the gut of Lampetra fluviatilis are characterized by histochemical, electron microscopical and biochemical methods. Strongly yellow fluorescent, probably serotonin-containing intrinsic neurons are found along the entire length of the intestine. Their processes aggregate to form large bundles of mainly non-terminal axons, constituting a subepithelial fibre plexus. This subepithelial, ganglion cell comprising plexus is connected to a wide-meshed subserosal plexus which has ganglion cells of different size and few varicose, single axons. Intermingled with both plexus there occur — in the anterior and middle but not in the preanal portion of the lamprey intestine — scattered green fluorescent intrinsic perikarya, emanating faintly green fluorescent, poorly varicosed axons. The formaldehyde-induced neuronal fluorophores conform to serotonin (yellow fluorescent compound), noradrenaline, and dopamine (green fluorescent substance), as revealed in microspectrofluorimetric recordings. The electron microscopical analysis of the yellow fluorescent intrinsic neurons in the terminal hindgut shows nerve cell pericarya and axons equipped with a typical population of occasional small granular and many large granular vesicles (750–1600 Å). The number and opacity of cores of the small and the osmiophilia of the cores of the large granular vesicles are significantly increased following short-term treatment with 5,6-dihydroxytryptamine. Long-term treatment with 5,6- or 5,7-dihydroxytryptamine provokes severe signs of ultrastructure impairment and eventual degeneration in the supposed serotonin-containing axons, besides indications of piling-up of organelles in the non-terminal axons due to arrest of axonal transport. Chromatography of acid extracts from the lamprey intestine, gills and kidney reveals the presence of serotonin (besides another unidentified indoleamine) and dopamine and noradrenaline in the gut, but only dopamine in the brain. The detection of serotonin, noradrenaline and dopamine in the lamprey gut is confirmed by chemical determinations. The occurrence of intrinsic serotonin-, noradrenaline- and dopamine-containing neurons in the gut of Lampetra fluviatilis deviates from the established pattern of innervation of the vertebrate intestine and is considered to be a remnant of an autonomic innervation principle common in invertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307395
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  • 136
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    Aspects histologique, histochimique et ultrastructural des péricaryones neurosécréteurs latéraux du protocérébron de Locusta migratoria migratorioides (Insecte: Orthoptère) (1973)
    Springer
    Cell & tissue research 141 (1973), S. 75-91 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretory cells ; Lateral ; Locust ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'étude histologique, histochimique et ultrastructurale des péricaryones neurosécréteurs latéraux de Locusta précise leur nombre et leur localisation. Elle révèle que le neurosécrétat latéral est semblable morphologiquement (forme et diamètre des granules élémentaires) au neurosécrétat A de la pars intercerebralis. Cependant, il en diffère histochimiquement par la présence d'une composante glucidique. Elle confirme l'hypothèse émise pour les péricaryones neurosécréteurs de la pars intercerebralis (Girardie et Girardie, 1967), de l'unicité cellulaire chez Locusta des types A et B selon la nomenclature de Johansson (1958). Elle suggère que les péricaryones latéraux pourraient être des cellules neurosécrétrices très actives.
    Notes: Summary The number (8 to 12) and position of the lateral neurosecretory cells have been established in Locusta by a histological, histochemical and ultrastructural study. The neurosecretory material of the lateral cells contains glycoprotein and is, in this way, histochemically different from medial A cells neurosecretory material. However, the morphological aspect (shape, diameter) of elementary dense core vesicles in the lateral and medial A neurosecretory cells is similar. This study confirms the idea (Girardie and Girardie, 1967) that, in Locusta, A cells and B cells (Johansson, 1958) are in fact two physiological aspects of one cell type. It also suggests that the lateral cells could be very active neurosecretory cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307397
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  • 137
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    Die Feinstruktur der Kehlkopfmuskeln des Laubfrosches, Hyla arborea arborea (L.), im Vergleich zu einem Skelettmuskel (1973)
    Springer
    Cell & tissue research 141 (1973), S. 223-233 
    Details
    ISSN: 1432-0878
    Keywords: Laryngeal muscles ; Tree Frog, Hyla aborea arborea (L.) ; Fine structure ; Motor endplates ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Um Hinweise auf die Funktion des Kehlkopfes bei der Rufabgabe zu bekommen, führten wir eine vergleichende elektronenmikroskopische Untersuchung an den vier Kehlkopfmuskeln rufaktiver Laubfrösche durch. Zum weiteren Vergleich studierten wir auch einen Extremitätenmuskel. Die Kehlkopfmuskeln sind untereinander gleich gebaut, unterscheiden sich aber in mehrfacher Hinsicht vom Extremitätenmuskel: Ihre Myofibrillen sind nur ein Drittel so dick. Die Kehlkopfmuskeln enthalten sehr viele, auffallend große und dichte Mitochondrien; das sarcoplasmatische Retikulum ist mächtig entwickelt. Sie enthalten außerdem sehr viel Fett, das stets mit den Mitochondrien assoziiert ist. In beiden Muskeltypen kommt Glykogen vor; seine Menge ist in den Kehlkopfmuskeln jedoch größer als im Extremitätenmuskel. Die Zahl der motorischen Endplatten ist in den Kehlkopfmuskeln 25 mal höher als im M. plantaris longus. Die Zahl der Triaden pro Sarcomer und ihre Anordnung ist bei den beiden Muskeltypen gleich. Die Kehlkopfmuskeln winterstarrer Hyla-Männchen unterscheiden sich in ihrem Feinbau und Fettgehalt nicht von den Muskeln rufaktiver Tiere.
    Notes: Summary In order to obtain information on the function of the larynx during vocalization, a comparative electron microscopic study was made of the four laryngeal muscles of male tree frogs druing their vocalizing phase. A skeletal muscle (m. plantaris longus) was examined for comparison. The fine structure of the laryngeal muscles is uniform, but differs from skeletal muscles in several respects: the diameter of the myofibrils of the laryngeal muscles is only 1/3 that of the skeletal muscle. They contain many strikingly large and dense mitochondria. There is a strongly developed sarcoplasmic reticulum. Laryngeal muscles contain large quantities of fat which is always associated with mitochondria. Laryngeal muscles contain more glycogen than skeletal muscle. The number of motor endplates in laryngeal muscles is 25 times larger than in m. plantaris longus. The number of triads per sarcomere and their location is the same in both types of muscle. The laryngeal muscles of hibernating and active tree frogs do not show any difference with respect to fine structure and amount of fat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00311355
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  • 138
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    Electronic Resource
    Über die Glia im Hypoglossuskern der Ratte nach Axotomie (1973)
    Springer
    Cell & tissue research 141 (1973), S. 427-442 
    Details
    ISSN: 1432-0878
    Keywords: Hypoglossal nucleus (Rat) ; Axotomy ; Glia ; Microglia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Es wird unter besonderer Berücksichtigung der Glia über den Feinbau des Hypoglossuskerns normaler Albinoratten und nach Axotomie berichtet. Untersucht wurden Tiere vom 12.–90. Lebenstag. Folgende Ergebnisse sind neu: Weder bei jungen noch bei erwachsenen Ratten kommt im Hypoglossuskern Mikroglia vor. Etwa ab. 3. Tag nach Axotomie kann bei erwachsenen Tieren Mikroglia nachgewiesen werden. Sie entsteht aus aktivierten und proliferierten Oligodendrocyten und pericytenähnlichen Bindegewebszellen. Die Mikroglia umhüllt die Nervenzellen. Eine Aktivierung und Hypertrophie von Astrocyten erfolgt etwa ab 8. Tag nach Axotomie. Von diesem Tage an drängen sich Astrocytenfortsätze zwischen Mikroglia und Nervenzelloberfläche. Die Mikroglia beginnt zu degenerieren. Bei Jungtieren bewirkt die Axotomie nur geringgradige Veränderungen. Schon beim Normaltier findet man aktive Oligodendroglia und Astrocyten sowie häufig pericytenähnliche Bindegewebszellen.
    Notes: Summary The ultrastructure of the Nucleus hypoglossi in normal albino rats and following axotomy is described with special reference to the glia. Animals 12 to 90 days old were investigated. The following results are new: Normally in young and adult rats microglia is absent in the nucleus. Following axotomy from the 3rd day no microglia can be demonstrated in adult rats. It originates from activated and proliferated oligodendrocytes and pericyte-like cells of the vascular connective tissue. These cells surround the neurons. An activation and hypertrophy of astrocytes is visible from the 8th postoperative day on. Astrocyte processes make contacts with the perikarya and separate the microglia from the neurons. Microglia cells then show signs of degeneration. In young animals alterations following axotomy are only sparse. Already normally activated oligodendrocytes and astrocytes as well as pericyte-like connective tissue cells can be seen.
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    URL: http://dx.doi.org/10.1007/BF00307415
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  • 139
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    Electronic Resource
    Vinblastine-induced paracrystals and unusually large microtubules (macrotubules) in rat renal cells (1973)
    Springer
    Cell & tissue research 141 (1973), S. 443-458 
    Details
    ISSN: 1432-0878
    Keywords: Microtubules ; Vinblastine ; Kidney tubules ; Podocytes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vinblastine sulfate was administered to adult rats by intravenous injections. Kidney cortex was fixed after 1, 2, or 5 hours of treatment and studied by routine transmission electron microscopy. In control animals, cells of distal convoluted tubules possessed numerous microtubules with an average diameter of 280 Å. In treated animals, the microtubules of these cells were reduced in number, and paracrystalline inclusions characteristic of vinblastine treatment were common. Macrotubules (570 Å average diameter) were also present and often were seen close to, or in apparent continuity with, paracrystals. Since the work of others indicates that vinblastine-induced paracrystals contain microtubular protein (tubulin), observation of continuities between paracrystals and macrotubules is interpreted as evidence that macrotubules are also composed of tubulin and that macrotubules may become incorporated into paracrystals. Unlike the ordinary microtubules of cells of the distal tubules, vinblastine-induced macrotubules exhibited cross-striations in longitudinal view and subunit structure in cross section. Macrotubules and paracrystals were also observed in cells of the proximal convoluted tubule, mesangium, glomerular endothelium, parietal epithelium of Bowman's capsule, and visceral epithelium of Bowman's capsule. Continuities between macrotubules and paracrystals, although relatively common in occurrence in distal tubule cells, were only rarely seen in the other kinds of cells examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307116
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  • 140
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    Electronic Resource
    Histological and ultrastructural observations on wound healing in the freshwater pulmonate Lymnaea stagnalis (1973)
    Springer
    Cell & tissue research 141 (1973), S. 561-573 
    Details
    ISSN: 1432-0878
    Keywords: Wound healing ; Lymnaea stagnalis ; Amoebocytes ; Phagocytosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The process of wound healing in Lymnaea stagnalis was studied by light and electron microscopy. Snails were wounded by making incisions in the skin. The observations showed that the wounds are closed by muscular contraction and by formation of thrombi of blood amoebocytes. These thrombi form a large amoebocyte plug. During the first 72 hrs after incision thin tubules (diameter 175–225 Å) were observed between the amoebocytes in the plug. Possibly these tubules represent a blood clotting protein. The round amoebocytes constituting the plug can be regarded as normal blood amoebocytes. First, ultrastructurally they closely resemble the amoebocytes of the circulating blood. Second, not only blood amoebocytes but also plug amoebocytes of snails injected with India ink before incision contained ink particles, indicating that the cells are of one type. Apparently due to phagocytosis of cell debris the number of lysosomes in plug amoebocytes increased during the first days after incision. Eighteen to twenty four hrs after incision the first signs of differentiation of round plug amoebocytes into flattened cells were observed. Between these cells collagen was seen from 3–5 days after incision and onwards. It is suggested that these flattened amoebocytes produce collagen fibrils. These cells are structurally different from collagen producing fibroblasts and from muscle cells of the surrounding connective tissue. Transformations of amoebocytes into these two latter cell types were not found. Ninety days after incision the connective tissue in the wound area is still different from that on non-injured sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307125
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  • 141
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    Electronic Resource
    Effects of colchicine and vinblastine on neurotubules of the sciatic nerve and cholinesterases in the developing myoneural junction of the rat (1973)
    Springer
    Cell & tissue research 142 (1973), S. 193-204 
    Details
    ISSN: 1432-0878
    Keywords: Neuromuscular junction ; Development ; Cholinesterases ; Axonal transport, Neurotubules, Colchicine, Vinblastine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Colchicine (0.1 M) or vinblastine (0.01 M) was locally applied on the sciatic nerves of newborn rats. Both colchicine and vinblastine caused reversible disappearance of axonal neurotubules and appearance of increased amounts of neurofilaments at the site of application. Subsequent morphogenesis of myoneural junctions in the tibialis anterior muscle was studied after histochemical demonstration of acetylcholinesterase (AChE; E.C. 3.1.1.7) and non-specific cholinesterase (Ns. ChE; E.C. 3.1.1.8) activity in the myoneural area. Development of the postsynaptic muscle plasma membrane of the myoneural junction was arrested in the ipsilateral, but not in the contralateral control side, for a period of about three weeks following treatment with the test substances. After this delay the myoneural morphogenesis continued normally and neurotubules were seen in the axoplasm. Since disruption of neurotubules is likely to cause blockage of the intratubular axoplasmic transport system, it seems possible that the neurotrophic influence responsible for the development of the postsynaptic muscle membrane is mediated through a secretory product transported along axons intratubularly to the nerve endings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307032
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  • 142
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    Electronic Resource
    Saisonbedingte Veränderungen in der Morphologie der Leydigzellen von Rana esculenta (1973)
    Springer
    Cell & tissue research 142 (1973), S. 367-386 
    Details
    ISSN: 1432-0878
    Keywords: Testicular interstitial cells ; Rana esculenta ; Seasonal changes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Saisonabhängige Veränderungen in der Morphologie der Leydigzellen von Rana esculenta wurden über den Zeitraum eines Jahres in Licht- und Elektronenmikroskop untersucht. In den Monaten November bis Februar kommen im Zytoplasma der Leydigzellen kleine Mitochondrien des tubulären Typs, Vesikel des glatten endoplasmatischen Retikulum und freie Ribosomen vor, Fettvakuolen treten nur vereinzelt auf, der Golgikomplex ist gering entwickelt. In der Zeit von März bis Juni nimmt die Zahl der Zellorganellen zu. Es erscheinen in Gruppen angeordnete Lysosomen und außer den kleinen Mitochondrien Riesenmitochondrien, des Golgifeld ist größer, die Fettvakuolen sind vermehrt. Sowohl die kleinen als auch die Riesenmitochondrien enthalten Kristalle, die aus osmiophilen globulären Einschlußkörpern hervorzugehen scheinen. In den Monaten Juni/Juli ist fast der ganze Zelleib einer Leydigzelle von Fettvakuolen ausgefüllt. Die Zahl der Riesenmitochondrien und Lysosomen verringert sich, das Golgifeld ist wieder unauffällig. Eine Beziehung zwischen der Vermehrung und Entfaltung der Zellorganellen und der in der Literatur angegebenen Phase der gesteigerten Steroidproduktion konnte festgestellt werden. Das Auftreten der Riesenmitochondrien und Lysosomen und ihre Bedeutung für die saisonbedingte Entwicklung und Involution der Leydigzellen wird diskutiert.
    Notes: Summary Seasonal changes in the structure of the testicular interstitial cells in Rana esculenta were investigated. Throughout November–February, small mitochondria of the tubular type, visicles of the smooth endoplasmic reticulum and free ribosomes predominate and the cytoplasm contains few lipid droplets and a poorly developed Golgi apparatus. During the period from March to June the cell organelles increase in number. There are numerous aggregated lysosomes and conspicuous accumulations of lipid droplets. Besides small mitochondria increasing numbers of giant mitochondria occur and the Golgi complex is enlarged. The small and giant mitochondria contain crystals which seem to originate from osmiophilic globular inclusion bodies. During June and July the whole cytoplasm may be filled with lipid droplets. Concomitantly there is a decrease in the number of lysosomes and giant mitochondria and the Golgi apparatus is in a state of involution. Possible correlations between the development of the cell organelles and the period of increased steroid production are pointed out. The appearance of giant mitochondria and lysosomes and their importance for seasonal Leydig cell development and involution are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307358
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  • 143
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    Electronic Resource
    Effects of testosterone, hydrocortisone and insulin on the fine structure of the epithelium of rat ventral prostate in organ culture (1973)
    Springer
    Cell & tissue research 143 (1973), S. 425-438 
    Details
    ISSN: 1432-0878
    Keywords: Prostate ; Tissue culture ; Androgens ; Hormones ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The explants of the rat ventral prostate were cultured on a chemically defined medium and the effects of individual hormones viz. testosterone, hydrocortisone and insulin on the fine structure of the epithelial cells were investigated. The epithelial cells without hormones underwent regressive changes resembling those seen in vivo after castration. Large autophagic vacuoles, residual bodies and dilations of rough endoplasmic reticulum (ER) were noted on day 2 of the culture. Four days later the amount of rough ER was markedly decreased and no secretory vesicles were visible. The treatment of the explants with testosterone resulted in an apparent intensification of the morphological equivalents of secretion. Beside the well developed rough ER and Golgi complex, numerous large secretory vesicles with flocculent content were observed. These observations are compatible with the idea that testosterone promotes the formation and probably also the excretion of the secretion in the epithelial cells. Testosterone also prevented partially the appearance of the signs of cellular degeneration. The most characteristic feature of hydrocortisone-treated epithelial cells was the copious supply of rough ER. Of particular interest was the formation of endoplasmic reticulum whorls which could not be observed in control and testosterone-treated cells. Hydrocortisone was shown to promote the formation of juvenile secretory vesicles on the second day. Insulin delayed the onset of the degeneration of the epithelial cells. Marked degenerative changes were, however, noted on day 6. There was no specific ultrastructural characteristic that could be interpreted to be specific for insulin action in the epithelial cell.
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    URL: http://dx.doi.org/10.1007/BF00307425
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  • 144
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    Electronic Resource
    The terminal neuromuscular junctions of lower chordates (1973)
    Springer
    Cell & tissue research 143 (1973), S. 495-504 
    Details
    ISSN: 1432-0878
    Keywords: Neuromuscular junction ; Teleosts and amphibia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of the terminal neuromuscular junctions found close to the insertions of myotomal muscle fibres in teleost fish and amphibia is described, and it is concluded that in both groups, the pattern of innervation is essentially similar. Different degrees of complexity are described, both in the terminal nerve branches, and in the sub-junctional apparatus. It is suggested that the terminal pattern of innervation is an adaptation to the requirements of rapid swimming.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306768
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  • 145
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    Electronic Resource
    Localization of tritiated prostaglandin E1 in rat adrenal cortices (1973)
    Springer
    Cell & tissue research 146 (1973), S. 309-317 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Prostaglandin E1 ; Autoradiography ; Electron microscopy ; Lipid analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To determine whether or not prostaglandins enter adrenocortical parenchymal cells,3H-PGE1 was injected intravenously into rats. In histological preparations, grains denoting activity were noted in intracellular lipid droplets and nuclei and in sinusoids. At the fine structural level, activity was observed in lipid droplets, mitochondria, the agranular endoplasmic reticulum, nuclei and the plasma membrane. Biochemical lipid analyses of the adrenals revealed activity in the cholesterol and cholesterol ester fractions. Large amounts of unaltered3H-PGE1 and its degradation products were also present. Compared to the liver, the adrenal was more effective in degrading prostaglandin, when expressed on a weight basis. The possible roles of the organelles in PGE1 degradation and in prostaglandin-related hormone synthesis are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02346223
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  • 146
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    Electronic Resource
    Fine structure and innervation of the avian adrenal gland (1973)
    Springer
    Cell & tissue research 146 (1973), S. 385-402 
    Details
    ISSN: 1432-0878
    Keywords: Interrenal cells ; Avian adrenal gland ; Lipid exocytosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cords of interrenal-cells of birds resemble “tubes without lumina”, which are lined by columnar cells arranged in double rows. A subcapsular and an inner zone of the interrenal gland may be distinguished according to the structure of their mitochondria, the existence of smooth and rough surfaced endoplasmic reticulum, and the lipid contents. The cells of the inner zone are clearly polarized. The extrusion of lipid by exocytosis is discussed. It is often difficult to decide, whether ultrastructural details are species - specific or indicate a certain state of function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02346230
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  • 147
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    Electronic Resource
    Fine structure and innervation of the avian adrenal gland (1973)
    Springer
    Cell & tissue research 145 (1973), S. 557-575 
    Details
    ISSN: 1432-0878
    Keywords: Avian adrenal gland ; Adrenergic nerve fibers ; p-Type nerve fibers ; 6-Hydroxydopamine ; Fluorescence microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Apart from cholinergic nerve fibers, which make up the main part of efferent fibers to the avian adrenal gland (Unsicker, 1973b), adrenergic, purinergic and afferent nerve fibers occur. Adrenergic nerve fibers are much more rare than cholinergic fibers. With the Falck-Hillarp fluorescence method they can be demonstrated in the capsule of the gland, in the pericapsular tissue and near blood vessels. By their green fluorescent varicosities they may be distinguished characteristically from undulating yellow fluorescent ramifications of small nerve cells which are found in the ganglia of the adrenal gland and below the capsule. The varicosities of adrenergic axons exhibit small (450 to 700 Å in diameter) and large (900 to 1300 Å in diameter) granular vesicles with a dense core which is usually situated excentrically. After the application of 6-hydroxydopamine degenerative changes appear in the varicosities. Adrenergic axons are not confined to blood vessels but can be found as well in close proximity of chromaffin cells. Probably adrenergic fibers are the axons of large ganglion cells which are situated mainly within the ganglia of the adrenal gland and in the periphery of the organ and whose dendritic endings show small granular vesicles after treatment with 6-OHDA. A third type of nerve fiber is characterized by varicosities containing dense-cored vesicles with a thin light halo, the mean diameter (1250 Å) of which exceeds that of the morphologically similar granular vesicles in cholinergic synapses. Those fibers resemble neurosecretory and purinergic axons and are therefore called p-type fibers. They cannot be stained with chromalum-hematoxyline-phloxine. Axon dilations showing aggregates of mitochondria, myelin bodies and dense-cored vesicles of different shape and diameter are considered to be afferent nerve endings. Blood vessels in the capsule of the gland are innervated by both cholinergic and adrenergic fibers.
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    URL: http://dx.doi.org/10.1007/BF00306724
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  • 148
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    Electronic Resource
    Electron microscopic studies on guinea pig rib cartilage (1973)
    Springer
    Cell & tissue research 146 (1973), S. 83-102 
    Details
    ISSN: 1432-0878
    Keywords: Cartilage (Guinea pig) ; Chondrocytes ; Proteoglycans ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The guinea-pig rib cartilage consists of chondrocytes dispersed in an intercellular substance composed of collagen fibrils, often characteristically cross-striated, and polygonal granules. Electron-dense membrane-bounded matrix vesicles are also observed intercellularly, especially in the central, partly calcified zone of the cartilage. With respect to their location in a cross-section of the rib, the chondrocytes differ in size, shape and intracellular fine structure. Thus, three separate types of cells are recognized. Peripheral chondrocytes have a flattened shape and are largely occupied by the nucleus. In the cytoplasm, the granular endoplasmic reticulum is the most extensive organelle. Intermediate chondrocytes are oval or round in shape. The endoplasmic reticulum and the Golgi complex are both prominent. Mitochondria and membrane-bounded cytoplasmic dense bodies are more numerous than in the peripheral cells. The ground cytoplasm often contains a few lipid droplets. In the central chondrocytes, such droplets sometimes fill the entire cytoplasm. Concomitantly, the nucleus is usually completely heterochromatic and the cells are therefore regarded as being metabolically inert. After preparations including ruthenium red staining en bloc, the general stainability of the chondrocytes is decreased. Intracellularly, positive ruthenium red staining of granular material within the Golgi vacuoles are to be observed. Extracellularly, the matrix granules are stained with this polyvalent, cationic dye. Extraction of the cartilage with 4 M guanidine-HCl removes all matrix granules and about 70% of the proteoglycans, measured as hexosamine, from the tissue. It is concluded that the matrix granules contain proteoglycan complexes.
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    URL: http://dx.doi.org/10.1007/BF00306760
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  • 149
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    Electronic Resource
    Pigment movements in fish melanophores: Morphological and physiological studies (1973)
    Springer
    Cell & tissue research 147 (1973), S. 107-125 
    Details
    ISSN: 1432-0878
    Keywords: Melanophores ; Teleost (Pterophyllum scalare) ; Pigment migration ; Microtubules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the melanophores of Pterophyllum scalare was studied with respect to changes in cell shape during melanosome migration and the number and distribution of microtubules within the cell extensions. Cells were fixed with pigment fully aggregated or fully dispersed. All measurements were carried out on cross sections of cell processes, i.e. sections cut perpendicular to the long axis of the cell extensions. Cross sections of processes of melanophores with dispersed pigment are more or less ovoid in shape, and microtubules are arranged predominantly just below the cell membrane. These microtubules exhibit a relatively constant centre-to-centre spacing of about 55–65 nm. Processes of melanophores with aggregated pigment seem to be collapsed; their volume is substantially decreased but their circumference equals that of dispersed melanophores. The number of microtubules is reduced, and their regular arrangement is lost. The differences in microtubule number associated with the aggregated or dispersed state occur irrespective of the nature of the agent inducing dispersion or aggregation. In addition, apparent insertion of microtubules into the plasma membrane of the cell processes and associations of microtubules with cytoplasmic densities in the cell centre are described. The results indicate a rapid disassembly and assembly of microtubules associated with pigment movements. The possible role of microtubule associations with cell membrane and densities as sites of microtubule polymerization is briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306603
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    Gezielte Synthese von Sulfinato-O- und -S-Komplexen einiger Übergangsmetalle, VII. Sulfinato-Komplexe von Chrom (II), Mangan(II), Eisen(II), Kobalt(II) und Nickel(II) mit ein- und zweizähnigen Stickstoffliganden (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 211-219 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Directed Synthesis of Sulfinato-O and -S Complexes of some Transition Metals, VII. Sulfinato Complexes of Chromium(II), Manganese(II), Iron(II), Cobalt(II) and Nickel(II) with Mono- and Bidentate Nitrogen Ligands.The hitherto unknown, pseudooctahedral configurated bis(organosulfinato-O,O')dipyridine compounds of manganese(II), iron(II), cobalt(II) and nickel(II) 5a, b and 6a-8a are obtained by the reaction of the complexes (p-R-C6h4SO2)2M(OH2)2 1a, b and 2a-4a with pyridine according to equation (1). Linkage or stereo isomers cannot be detected.  -  White (p-CH3C6H4SO2)2Cr(OH2)2 (9) reacts with 2 moles of 2,2′-bipyridyl in water according to equation (2) to form the sulfinato-O complex 10, the corresponding manganese compound 1a adds only 1 mole of 2,2′-bipyridyl according to equation (3), yielding the sulfinato complex 11O,O'. In the case of 9 other solvents are not leading to linkage isomers. In contrast to this the sulfinato complex 11S, being linkage and structural isomeric to 11O,O' is obtained from 1a and 2,2′-bipyridyl in pyridine according to equation (4). The iron compound 2c reacts only in THF with 2 moles of 2,2-bipyridyl according to equation (5) to give the sulfinato complex 12O, which is in pyridine irreversibly converted into the S-isomer 12S according to equation (6). 12S can also be isolated from 2c and 2 moles of 2,2′-bipyridyl in pyridine according to equation (7). The newly prepared compounds are characterized on the basis of their i.r. and their electronic spectra as well as by magnetochemical investigations.
    Notes: Bei der Umsetzung der Komplexe (p-R C6H4SO2)2M(OH2)2 1a,b und 2a-4a mit Pyridin erhält man gemäß Gl. (1) die bisher unbekannten, pseudooktaedrisch konfigurierten Bis(organosulfinato-O,O')-dipyridin-Verbindungen von Mangan(II), Eisen(II), Kobalt(II) und Nickel(II) 5a, b und 6a-8a. Bindungs- oder Stereoisomere lassen sich nicht nachweisen.  -  Während (p-CH3C6H4SO2)2Cr(OH2)2 (9) in Wasser gemäß Gl. (2) 2 mol 2,2′-Bipyridyl unter Bildung des Sulfinato-O-Komplexes 10 aufnimmt, addiert die entsprechende Mangen-Verbindung 1a gemäß Gl. (3) nur 1 mol 2,2′-Bipyridyl, wobei der Sulfinato-Komplex 11O,O' entsteht. Andere Lösungsmittel führen bei 9 zu keinen Bindungsisomeren. Dagegen erhält man aus 1a und 2,2′-Bipyridyl in Pyridin entsprechend Gl. (4) den zu 11O,O' bindungs- und strukturisomeren Sulfinato-Komplex 11S. Die Eisen-Verbindung 2c setzt sich nur in THF mit 2 mol 2,2′-Bipyridyl gemäß Gl. (5) zum Sulfinato-O-Komplex 12O um, welcher in Pyridin irreversibel entsprechend Gl. (6) in das S-Isomere 12S übergeht 12S läßt sich gemäß Gl. (7) auch aus 2c und 2 mol 2,2′-Bipyridyl in Pyridin isolieren., Die neu dargestellten Verbindungen werden anhand ihrer IR- und Elektronenspektren, sowie durch magnetochemische Untersuchungen charakterisiert.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060126
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    Die Röntgenstrukturanalyse des 2 : 1-Cycloadditionsproduktes von Diazomethan und 4-Methyl-1,1-bis(trifluormethyl)-2-aza-1,3t-butadien (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 288-311 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: X-Ray Structure Analysis of the 2 : 1-Cycloaddition Product of Diazomethane and 4-Methyl-1,1-bis(trifluormethyl)-2-aza-1,3t-butadieneThe structure of 1-(4-methyl-1-pyrazolin-3-yl)-5,5-bis(trifluormethyl)-Δ2-1,2,3-triazoline (C8H9F6N5) (4a), which is the 2 : 1-cycloaddition product of diazomethane and 4-methyl-1,1-bis(trifluormethyl)-2-aza-1,3t-butadiene, was solved by direct methods. Space group: Pbca; a = 19.839 Å, b = 12.985 Å, c = 8.826 Å 8 molecules per unit cell. The refinement by least squares methods yielded a final R index of 5.5% (for 1900 observed reflexions). The hydrogen atoms have been included into the refinement.The constitution of the molecule, which on chemical and physical ways could not unambigously be determined, has been evaluated. The binding situation is discussed and including hydrogen atoms a detailed conformational analysis is carried out. The crystal structure is discussed, too. It contains an interesting type of a hydrogen-bridge system.
    Notes: Die Lösung der Struktur des 1-(4-Methyl-1-pyrazolin-3-yl)-5,5-bis(trifluormethyl)-Δ2-1,2,3-triazolins (C8H9F6N5) (4a), dem 2 : 1-Cycloadditionsprodukt von Diazomethan und 4-Methyl-1,1-bis(trifluormethyl)-2-aza-1,3t-butadien erfolgte mit direkten Methoden. Raumgruppe: Pbca; a = 19.839 Å, b = 12.985 Å, c = 8.826 Å, mit 8 Molekülen pro Elementarzelle. Die Verfeinerung nach der Methode der kleinsten Quadrate konvergierte unter Einschluß der H-Atome bei einem R-Wert von 5.5% (für 1900 beobachtete Reflexe).DIE KONSTITUTION der Molekel, die auf chemisch-physikalischem Wege nicht eindeutig bestimmt werden konnte, wurde festgelegt. Es werden die Bindungsverhältnisse diskutiert und unter Einbeziehung der Wasserstoffatome eine detaillierte Konformationsanalyse durchgeführt. Gleichfalls wird auf die Kristallstruktur, die einen interessanten Typ eines Wasserstoffbrückensystems enthält, eingegangen.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060133
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  • 152
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    Zur Hydrierung von Δ2-5-Isoxazolonen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 332-338 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Hydrogenation of Δ2-5-IsoxazolonesThe Δ2-5-isoxazolones 1, 5, 8a-c, and 11a, b are opened under conditions of the catalytic reduction to yield β-enamino-β'-ketocarboxylic acids 6a, b. In a second step, the derivatives 8a-c, 11a, b form diazepines 10a-c and pyrazoles 12, 13 by intramolecular cyclization. The structures are elucidated on the basis of the n.m.r. and i.r. spectra.
    Notes: Die Δ2-5-Isoxazolone 1, 5, 8a-c und 11a, b werden bei der katalytischen Hydrierung unter reduktiver Ringöffnung zu β-Enamino-β'-ketocarbonsäuren 6a, b gespalten Dabei cyclisieren die Derivate 8a-c, 11a, b intramolekular zu den Diazepinen 10a-c und Pyrazolen 12, 13. Die Strukturen werden durch NMR- und IR-Spektren bewiesen.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060136
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    Masthead (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060201
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  • 154
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    Abfangreaktionen kurzlebiger Radikale, IX1) Zum radikalisch induzierten Zerfall von Peroxycarbonsäureestern: SH2-Reaktion und radikalisch katalysierte Fragmentierung als konkurrierende Mechanismen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 411-420 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Short-Life Radicals, IX1) Radical-Induced Decomposition of Esters of Peroxycarboxylic Acids: SH2 Reaction and Radical-Catalysed Fragmentation as Competing MechanismsThe radical decomposition of peresters RC(O)—O—OC(CH3,)3 R = C6H5, CH3, C(CH3)3 (1a-c) is induced very strongly by triethyltin hydride. A SH2 reaction and a radicalcatalysed fragmentation (a new type of reaction) are found to be competing mechanisms here. In both cases the stannyl radical is the attacking species. In the former reaction, splitting of the O—O bridge occurs with formation of the stannyl esters 3a-c. In the latter R· +CO2 ·OC(CH3) are formed, while the attacking radical is recovered. All products have been identified and quantitatively determined. From hall-life times and rate constants in the range of 21 -3O°, the following values have been calculated for the two competing reactions at 25° in the case of 1c: for the SH2 reaction ΔG+ = 22.7 kcal/mole, ΔS≠ = -19 e. u.; for the fragmentation ΔG≠ = -22.4 kcal/mole, ΔS+ = - 12 e. u. With 1a, the SH2 reaction dominates under all conditions. The importance of the competing catalysed fragmentation, however, increases greatly in the sequence 1a 〈 1b 〈 1c, and can become the main reaction. Dissociation energies and inductive effects of R, stereochemistry of transition states, temperature, and polarity of solvents are found to be of considerable influence.
    Notes: Der radikalische Zerfall von Perestern RC(O)—O—OC(CH3)3, R = C6H5, CH3, C(CH3)3 (1a-c) wird durch Triäthylzinnhydrid sehr stark induziert. Als konkurrierende Mechanismen werden eine SH2-Reaktion und, als neuartiger Reaktionstyp, eine radikal-katalysierte Fragmentierung beobachtet. In beiden ist das Stannyl-Radikal angreifendes Agens, in einem Fall unter Spaltung der O—O-Brücke und Bildung der Stannylester 3a-c, im anderen unter Bildung von R· +CO2 + ·OC(CH3)3 und Rückgewinnung des angreifenden Radikals. Entstehende Produkte werden qualitativ und quantitativ bestimmt. Für 1c ergibt sich aus Halbwertszeiten und Geschwindigkeitskonstanten im Bereich 21-30° für SH2-Reaktion bzw. Fragmentierung bei 25°: ΔG≠ = 22.7 kcal/mol, ΔS≠ = -19 e. u. bzw. 22.4 kcal/mol, -12 e. u. - Bei 1a überwiegt stets die SH2-Reaktion. In der Reihe 1a 〈 1b 〈 1c tritt jedoch die konkurrierende katalysierte Fragmentierung immer stärker hervor und kann zur Hauptreaktion werden. Dissoziationsenergien und induktive Effekte von R, die Stereochemie der Übergangszustände, Temperatur und Polarität des Lösungsmittels haben hierauf beträchtlichen Einfluß.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060208
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    Tautomerie von Heterocyclen, I. Über die Tautomerie von “4-Chinazolylthioharnstoffen” und verwandter Verbindungen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 471-483 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tautomerism of Heterocyclic Compounds, I. The Prototropic Tautomerism of “4-Quinazolylthioureas” and Related CompoundsThe prototropic tautomerism and hydrogen-bonding interactions of 4-quinazolylthioureas, -thioamides and a thiocarbamic acid ester are studied by spectroscopic methods (i. r. and n. m. r.). In case of thiocarbamic acid ester both tautomeric forms (10 and 11) can be isolated as crystalline solids.
    Notes: Die Tautomerieerscheinungen und Wasserstoffbrückenbeziehungen bei 4-Chinazolylthioharnstoffen, -thioamiden und einem -thiourethan werden IR- und NMR-spektroskopisch untersucht. Im Falle des Thiourethans können beide Tautomeren (10 und 11) in Substanz isoliert werden.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060213
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  • 156
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    Polyacetylenverbindungen, 2131) Neuartige natürliche Schwefelacetylen-Verbindungen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 497-504 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polyacetylenic Compounds, 2131) Novel Natural Sulphur Acetylenic CompoundsThe structures and configurations of four sulphur compounds isolated from Berkheya barbata (L. f.) Hutch. are established by synthesis of the two possible structure type (1 and 17)
    Notes: Die Konstitutionen und Konfigurationen von vier aus Berkheya barbata (L. f ) Hutch. isolierten Schwefel-Verbindungen werden durch Synthese der beiden möglichen Strukturtypen geklärt (1 und 17).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060216
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  • 157
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    Masthead (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060101
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  • 158
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    Über eine [3 + 1]-Cycloaddition, II. Reaktionen von 4,5-Dihydro-1,3,5-oxazaphosph(V)olen, VI (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1-7 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On a [3 + 1] Cycloaddition, II. Reactions of 4,5-Dihydro-1,3,5-oxazaphosph(V)olen, VI4,5-Dihydro-1,3,5-oxazaphosph(V)oles 1 react with isonitriles to yield disubstituted 3-imino-4,4-bis(trifluoromethyl)-1-azetines 2 with elimination of phosphoric acid esters. The reaction should proceed via nitrile ylides.
    Notes: 4,5-Dihydro-1,3,5-oxazaphosph(V)ole 1 reagieren mit Isonitrilen zu disubstituierten 3-Imino-4,4-bis(trifluormethyl)-1-azetinen 2 unter Ehmmierung von Phosphorsäureester Eine Nitrilylid-Zwischenstufe wird angenommen.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060102
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  • 159
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    17β-Cyclobutenylsteroide (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 882-887 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 17β-CyclobutenylsteroidsThe 21-mesylate derivative 1c of 3β,21-diacetoxy-5α-pregnan-20-one (1a) reacts with dimethyl(methylene)sulfonium oxide to give the aldehyde 2. Reduction of the aldehyde leads to the corresponding alcohol 3, which is easily dehydrated with ring expansion to the cyclobutenyl derivative 4a. After saponification and oxidation 17β-(1-cyclobuten-1-yl)-5α-androstan-3-one (5) is obtained.
    Notes: Ausgehend vom 3β,21-Diacetoxy-5α-pregnan-20-on (1a) gelangt man durch Umsetzung des 21-Mesylats 1c mit Dimethyl(methylen)sulfoniumoxid zum Aldehyd 2. Nach Reduktion zum Alkohol 3 erfolgt leicht Dehydratisierung unter Ringerweiterung zum Cyclobutenyl-Derivat 4a. Nach Verseifung und Oxidation erhält man das 17β-(1-Cyclobuten-1-yl)-5α-androstan-3-on (5).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060319
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    Bildungsmechanismus von 4-Amino-5-aminomethyl-2-methylpyrimidin aus 3-Äthoxy-2-(diäthoxymethyl)propionitril und Acetamidin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 893-901 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mechanism of the Formation of 4-Amino-5-aminomethyl-2-methylpyrimidine from 2-(Diethoxymethyl)-3-ethoxypropionitrile and AcetamidineThe mechanism of the formation of 4-amino-5-aminomethyl-2-methylpyrimidine (3) from 2-(diethoxymethyl)-3-ethoxypropionitrile (5) and acetamidine has been investigated by means of labelled compounds 5 which contained the C ≡ 15N, 14C ≡ N, and 14CH(OC2H5)2, respectively. The labelled 3 was subjected to a series of degradation reactions. From the distribution of the isotopes it has been proved as follows: The nitrogen of the C ≡ N group is incorporated either into the 3-position or into the amino group at the 4-position of 3 in a ratio of ca. 1 : 1. The carbon atom at 6-position originates from HCO2R. The formation of 3 probably proceeds through the routes c and d.
    Notes: Der Bildungsmechanismus von 4-Amino-5-aminomethyl-2-methylpyrimidin (3) aus 3-Äthoxy-2-(diäthoxymethyl)propionitril (5) und Acetamidin wurde mittels markiertem 5, das die C ≡ 15N-, 14C ≡ N- bzw. die 14CH(OC2H5)2-Gruppe enthielt, untersucht. Das markierte 3 wurde einer Reihe von Abbaureaktionen unterworfen. Aus der Verteilung der Isotope ergibt sich, daß der Stickstoff der C ≡ N-Gruppe in 3-Stellung oder in die 4-Aminogruppe von 3 mit einer Wahrscheinlichkeit von ca. 1 : 1 eingebaut wird. Der Kohlenstoff in 6-Stellung leitet sich aus HCO2R ab. Die Bildung von 3 verläuft wahrscheinlich auf den Wegen c und d.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060321
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    Tris(chlormethyl) amin und Bis(chlormethyl)methylamin. Darstellung und chemische Reaktionen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 69-77 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tris(chloromethyl)amine and Bis(chloromethyl)methylamine. Synthesis and Chemical ReactionsThe title compounds (1, 8) were synthesized by reaction of PCl5 with hexamethylenetetramine or 1,3,5-trimethylhexahydro-s-triazine, respectively. The reactions of 1 and/or 8 with SbCI5, SnCl4, sodium methylate, sodium acetate, phenyllithium, Grignard compounds, sec. amines and ethanethiol are described. The reaction products, tertiary amines, partially unknown as yet, are characterized.
    Notes: Die Titel-Verbindungen (1,8) wurden durch Umsetzung von PCl5 mit Hexamethylentetramin bzw. 1,3,5-Trimethylhexahydro-s-triazin dargestellt. Die Reaktionen von 1 und/oder 8 mit SbCl5. SnCl4, Natriummethylat, Natriumacetat, Phenyllithium, Grignard-Verbindungen, sek. Aminen und Äthanthiol werden beschrieben. Die Reaktionsprodukte, teilweise bislang nicht beschriebene tertiäre Amine, werden charakterisiert.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060111
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    Fragmentierungsreaktionen an Carbonylverbindungen mit β-ständigen elektronegativen Substituenten, XXIII. cis- und trans-4.4.8.8-Tetraalkyl-2.6-dioxa-bicyclo[3.3.0]octane aus 1.6-Bis-p-toluolsulfonyloxy-2.2.5 5-tetraalkyl-hexandionen-(3.4) (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 91-104 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fragmentation Reactions of Carbonyl Compounds with Electronegative ß-Substituents, XXIII cis- and trans-4.4.8.8-Tetraalkyl-2.6-dioxabicyclo[3.3.0]octanes from 1.6-Bis(tosyloxy)-2.2.5.5-tetraalkyl-3.hexandionesDiketoditosylates 8 and 9a-c are prepared and reduced with NaBH4. 8 yields 16a and a cis-trans mixture of 23; 9a-c afford the tetrahydrofuranols 14a-c and the cis-2.6-dioxabicyclo[3.3.0]octanes 21a-c. 14a-c and 16a react with NaOH in methanol to form the pure trans-compounds 21a-c and 23. Solvolysis of 9a with excess NaOH in methanol leads to the tetrahydrofuranone 13a and to the bicyclo acetal 22a. Solvolysis of 9b with only 2 equivalents of NaOH yields thc intermediate 12, which can be isolated and converted to 13b and 22b.The trispiro compound 27 is isolated as an unexpected side product from the NaBH4-reduction of 9b.
    Notes: Die Diketo-ditosylate 8 und 9a-c werden dargestellt und mit NaBH4 reduziert. 8 liefert 16a und ein cis-trans-23-Gemisch, aus 9a-c werden die Tetrahydrofuranole 14a-c und die cis-2.6-Dioxa-bicyclo[3.3.0]octane 21a-c erhalten. 14a-c und 16a reagieren mit NaOH in Methanol zu den reinen trans-Verbindungen 21a-c und 23. Die Solvolyse von 9a mit überschüssigem NaOH in Methanol führt zu dem Tetrahydrofuranon 13a und dem bicyclischen Acetal 22a. Mit 2 Äquivv. NaOH kann aus 9b die Zwischenstufe 12 isoliert und erneut zu 13b und 22b umgesetzt werden.Als ungewöhnliches Nebenprodukt tritt bei der NaBH4-Reduktion von 9b die Trispiroverbindung 27 auf.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19731060113
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    Asterane, IX. Synthese und Struktur von Tetramethyltetraasteranen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 150-156 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asteranes, IX. Synthesis and Structure of Tetramethyltetraasteranes1,2,7,8- and 1,4,5,8-tetramethylpentacyclo[6.4.0.02.7.04.11.05.10.]dodecane (3 and 6) are obtained by Wolff-Kishner reduction of the cage dimers from 2,3- and 2,5-dimethyl-p-benzoquinone via the tetrahydrazones 2 and 5. The structure of 6 is confirmed by X-ray-diffraction analysis.
    Notes: Wolff-Kishner-Reduktion überführt die Käfigdimeren aus 2,3- und 2,5-Dimethyl-p-benzochinon in 1,2,7,8- und 1,4,5,8-Tetramethylpentacyclo[6.4.0.02.7.04.11.05.10]dodecan (3 und 6), wobei es notwendig ist, die Tetrahydrazone 2 und 5 zu isolieren. Die Struktur von 6 wird durch Röntgenanalyse bestätigt.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060118
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  • 164
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    Natürlich vorkommende Cumarin-Derivate, IX1) Über die Inhaltsstoffe der Gattung Gerbera (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 382-387 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occuring Coumarin Derivatives, IX1) On the Constituents of the Genus GerberaThe roots of several Gerbera species contain the known polyynes 1 and 2. In addition from Gerbera crocea the acetophenon derivative 3 and two new coumarins (4 and 7) were isolated, the structures being elucidated by spectroscopic data as well as by synthesis.
    Notes: Die Wurzeln mehrerer Gerbera-Arten enthalten die bekannten Polyine 1 und 2. Aus Gerbera crocea wurden zusätzlich das Acetophenon-Derivat 3 und zwei neue Cumarine (4 und 7) isoliert, deren Strukturen durch spektroskopische Daten sowie durch Synthese geklärt werden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060203
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  • 165
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    Über Aminosäuren und Peptide, VII1) Syntheseversuche in der Reihe der 3,6-Epidithio-2,5-dioxopiperazin-Antibiotika Gliotoxin, Sporidesmin, Aranotin, Chaetocin und Verticillin, VII1) Über die Einführung von Sauerstoffunktionen in Prolyl-prolinanhydrid mit Bleitetraacetat: Ein neuer Weg zum Epidisulfid des Prolyl-prolinanhydrids (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 396-398 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Amino Acids and Peptides, VII1) Studies in the Synthesis of the Antibiotics Gliotoxin, Sporidesmin, Aranotin, Chaetocin, and Verticillin, VII1) On the Introduction of Oxygen Functions in Prolyl-proline Anhydride with Lead Tetraacetate: A New Way to Epidithioprolyl-proline AnhydrideOxidation of L-prolyl-L-proline anhydride (1a) with lead tetraacetate affords 3,6-diacetoxy-L-prolyl-D-proline anhydride (2b). Reaction of 2b with ethanethiole yields cis-3,6-bis(ethylthio)prolyl-proline anhydride (3a), with thiolacetic acid :trans-3,6-bis(acetylthio)prolyl-proline anhydride (4b) is formed. Solvolysis with diluted aqueous acid leads to cis-3,6-di-hydroxyprolyl-proline anhydride (5a). By means of the reactions 1a → 2b → 5a a new way to epidithioprolyl-proline anhydride 6 was found.
    Notes: L-Prolyl-L-prolinanhydrid (1a) wird mit Bleitetraacetat zum 3,6-Diacetoxy-L-prolyl-D-prolinanhydrid (2b) oxidiert. 2b bildet mit Äthylmercaptan cis-3, h-Bis(äthylmercapto)prolyl-prolinanhydrid (3a) und mit Thioessigsäure trans-3,6-Bis(acetylmercapto)prolyl-prolin-anhydrid (4b). Durch Solvolyse mit verdünnter wäßriger Säure erhält man cis-3,6-Dihydroxy-prolyl-prolinanhydrid (5a). Durch dic Reaktionsfolge 1a → 2b → 5a ist ein neuer Weg zum Epidithioprolyl-prolinanhydrid 6 gegeben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060205
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  • 166
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    Nucleoside, VII1) Synthese von 2′-O-, 3′-O- und 5′-O-Benzylcytidin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 665-673 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleosides, VIII1) Synthesis of 2′-O-, 3′-O- und 5′-O-BenzylcytidineThe synthesis of the three monobenzyl ethers of cytidine 14, 15 und 19 by benzylation of N6-benzoyl-3′,5′- (4), N6-benzoyl-2′,5′-di-O-tritylcytidine (3) and N6-benzoyl-2′,3′-O-isopropylidenecytidine (21) via the NaH-method as well as removal of the various blocking groups is described. The newly synthesized compounds were characterized by variuos spectra.
    Notes: Die Synthese der drei Mono-O-benzyläther des Cytidins 14, 15 und 19 durch Benzylierung des N6-Benzoyl-3′,5′- (4), N6-Benzoyl-2′,5′-di-O-tritylcytidins (3) und N6-Benzoyl-2′,3′-O-isopropylidencytidins (21) mit der NaH-Methode und nachfolgender Schutzgruppenabspaltung wird beschrieben. Die neu synthetisierten Substanzen werden durch Spektren charakterisiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060232
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  • 167
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    Beiträge zur Chemie des Hydrazins und seiner Derivate, XXXIX1). Notiz zur Darstellung von 1,4-Dithia-2,3-diaza-1,1,4,4-cycloheptantetron (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 713-714 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060236
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  • 168
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    Über Metalltrifluorphosphin-Komplexe, XXXVIII1) Zur Kenntnis von (π-Dien)tris(trifluorphosphin)eisen(0)- Komplexen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 697-706 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metaltrifluorophosphine Complexes, XXXVIII1) On the Knowledge of (π-Diene)tris(trifluorophosphine)iron(0) ComplexesThe photochemical reaction between conjugated dienes 1′ - 13 and Pentakis(trifluorophosphine)iron(0) in ether solution yields (π-diene)tris(trifluorophosphine)iron(0) complexes. They are airstable and sublimable. Their 1H-n.m.r.-, i r - and mass spectra are discussed.
    Notes: Die photochemische Reaktion konjugierter Diene (1′ - 13′) mit Pentakis(trifluorphosphin)-eisen(0) in Äther führt zu luftstabilen, sublimierbaren Komplexen des Typs (π-Dien)tris(trifluorphosphin)eisen(0) (1-13). Ihre 1H-NMR-, IR- und Massenspektren werden diskutiert.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060234
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  • 169
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    Beiträge zur Chemie des Hydrazins und seiner Derivate, XXXVIII1) Zur Synthese schwefelsubstituierter Hydrazinderivate durch Hydrosulfurierung einer N = N-Doppelbindung (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 707-712 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Hydrazine and its Derivatives, XXXVIII1) On the Synthesis of Sulfur-substituted Derivatives of Hydrazine by Hydrosulfuration of a N=N Double BondAddition of the S — H-functions of thiophenol, p-methylthiophenol, p-chlorothiophenol, p-bromothiophenol, m-benzenedithiol, and 1,2-ethanedithiol to the N = N double bond of diethyl azodicarboxylate afforded the sulfur-substituted derivatives of hydrazine 1-6, which were obtained as colourless crystalline compounds. They were identified by i.r., n.m.r., and mass spectroscopic investigations.
    Notes: Durch Addition der S—H-Funktionen von Thiophenol, p-Methylthiophenol, p-Chlorthiophenol, p-Bromthiophenol, m-Benzoldithiol und Äthan-l,2-dithiol an die N = N-Doppelbindung des Azodicarbonsäure-diäthylesters konnten die schwefelsubstituierten Hydrazin-derivate 1-6 als farblose kristalline Verbindungen dargestellt werden. Sie wurden durch IR-, NMR- und massenspektroskopische Untersuchungen charakterisiert.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19731060235
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  • 170
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    Notiz zur Darstellung von 1,3-Dimercaptobenzol (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 719-720 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060239
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  • 171
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    Masthead (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060301
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  • 172
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    Reaktionen von Diazoalkanen mit α-Diketonen und Chinonen, XXI. Umsetzungen von Diazoalkanen mit 2,6-Dichlor-p-benzochinon (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 727-733 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Diazoalkanes with 2,6-Dichloro-p-benzoquinone. Reactions of Quinones and α-Dicarbonyl Compounds with Diazoalkanes, XXIIn the reaction of diazomethane and -ethane with 2,6-dichloro-p-benzoquinone (9) two diazoalkane molecules are added to the two C=C groups, one of the CO groups is epoxidized, and both NH groups are alkylated to form 7 (or 11). The intermediate products 5 and 6 (or 10) can be isolated. Diazoacetate reacts with 9 to yield the epoxide 15; 13 and 14 are assumed to be intermediates. Oxidative hydrolysis (with nitric acid) of 15 gives the dicarboxylic acid 12, which can be methylated with diazomethane to form the tetramethyl derivative 8. As expected, the latter is not identical with the isomer 4e, which is obtained from 2,5-dichloro-p-benzoquinone (1) and diazoacetate via the intermediate products 2c → 3d.
    Notes: Bei der Einwirkung von Diazomethan und -äthan auf 2,6-Dichlor-p-benzochinon (9) erfolgt Addition je einer Diazoalkan-Molekel an die beiden C=C-Doppelbindungen, Epoxidierung einer C=O-Gruppe und N-Alkylierung zu 7 bzw. 11, wobei die Chlor enthaltenden Zwischenprodukte 5, 6 bzw. 10 isoliert werden können. Mit Diazoessigester reagiert 9 unter Bildung des Epoxids 15, wobei 13 und 14 als Zwischenprodukte angenommen werden. Oxidierende Hydrolyse (mit Salpetersäure) baut das Epoxid 15 zur Dicarbonsäure 12 ab, die durch Diazomethan zum Diester 8 methyliert wird. Letzterer ist erwartungsgemäß nicht identisch mit dem aus 2,5-Dichlor-p-benzochinon (1) und Diazoessigester über die Zwischenprodukte 2e → 3d erhältlichen Diester 4e.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060302
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  • 173
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    Anlagerungs- und Eliminierungsreaktionen mit Schwefelsauerstoff-Verbindungen, II. Dihydroxyarylsulfone (und chinoide Folgeprodukte) durch Reaktion von Hydroxymethansulfinat (Rongalit C©) mit Chinonen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 798-802 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition and Elimination Reactions with Sulfur Oxygen Compounds, II. Dihydroxyarylsulfones (and Quinonoid Secondary Products) by Reaction of Hydroxymethanesulfinate (Rongalit C ©) with QuinonesThe reaction of hydroxymethanesulfinate with 1,4- and 1,2-benzoquinone as well as with 1,4-naphthoquinone. which can be generated in situ from the corresponding dihydroxyaryl compounds by oxidation, yields symmetrical bis(dihydroxyaryl) sulfones (e. g. 2,7). Oxidation of bis(2,5-dihydroxyaryl) sulfones of type 2 does not lead to bis-quinones 3, but to oxathiin S,S-dioxide monoquinones (4, 6) by cyclisation.
    Notes: Die Umsetzung von Hydroxymethansulfinat mit 1,4- und 1,2-Benzochinon sowie 1,4-Naphthochinon, die aus den entsprechenden Dihydroxyarylverbindungen oxidativ in situ erzeugt werden können, führt zu symmetrischen Bis(dihydroxyaryl)sulfonen (z. B. 2,7). Die Oxidation der Bis(2,5-dihydroxyaryl)sulfone vom Typ 2 ergibt keine Bis-chinone 3, sondern unter Ringbildung Oxathiin-S,S-dioxid-monochinone (4, 6).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060308
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  • 174
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    Die Photoelektronen-Spektren der Benzocycloalkene (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 961-969 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Photoelectron Spectra of BenzocycloalkenesThe PE. spectra of benzocycloalkenes 3 (n) with n = 3 to 8 have been recorded. It is shown that an attempt to interpret the influence of the alkyl moiety  -  [CH2]n-2 on the π-orbital energies ε(b1 (π)) and ε(a2(π)) by the simple inductive/hyperconjugative Hückel molecular orbital model of alkyl groups demands that the methylene group CH2 in 3 (3) and the ethylene group -[CH2]2- in 3 (4) be assigned negative and zero inductive effects, respectively. This in turn leads to the interpretation that the destabilization of the highest occupied π-orbitals b1(π) in 3 (3) and 3 (4) is due to hyperconjugation. The highest occupied σ-orbitals of the hydrocarbons 3 (n) are localized mainly in the CC-bonds of the cycloalkene part if n = 3 or 4 and in the CH-bonds if n ≥ 5.
    Notes: Die PE-Spektren der Benzocycloalkene 3 (n) mit n = 3 -8 wurden aufgenommen. Will man den Einfluß der Alkyleinheit -[CH2]n-2 auf die Orbitalenergien ε(b1 (π)) und ε(a2(π)) mittels eines Orbitalmodells erklären, welches im Rahmen der Hückelschen Näherung nur induktive und hyperkonjugative Parameter zuläßt, so findet man, daß der Methylengruppe CH2 in 3 (3) ein negativer, der Äthylengruppe.- [CH2]2 in 3 (4) ein verschwindender induktiver Effekt zuzuordnen ist. Dieses Ergebnis verlangt, daß die Destabilisierung des obersten besetzten π-Orbitals b1 (π) in 3 (3) und 3 (4) auf hyperkonjugative Wechselwirkungen zurückgeführt wird. Das oberste besetzte σ-Orbital der Kohlenwasserstoffe 3 (n) ist für n = 3 und 4 vor allem in den CC-Bindungen, für n ≥ 5 in den CH-Bindungen der Cycloalken-Einheit lokalisiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060330
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  • 175
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    Zur Kenntnis des Triselenadiborolan-Systems (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1012-1018 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Triselenadiborolane SystemSeveral methods for the synthesis of triselenadiborolanes (R-B)2Se3 (1-6) are described, and the formation and structure of the five-membered ring are discussed. The reaction of R2B-X (X = J, H) with selenium or dicyclopentadienyltitanium pentaselenide yields the hitherto unknown diboryldiselenanes, which decompose thermally to form the five membered ring, selenium and R3B. Replacement of the Se2 bridge in the ring by N,N'-dimethyl-hydrazine leads to a new boron-nitrogen-selenium heterocycle (9, 10).
    Notes: Es werden mehrere Darstellungsmethoden für Triselenadiborolane (R-B)2Se3 (1-6) be-schrieben sowie die Bildung und Struktur des Fünfringes diskutiert. Bei Umsetzungen von R2B-X (X = J, H) mit Selen bzw. mit Dicyclopentadienyltitanpentaselenid entstehen die bisher unbekannten Diboryldiselenane R2B-Se-Se-BR2, welche thermisch in den Fünf-ring, Selen und R3B zerfallen. Substitution der Se2-Brücke im Ring durch N,N'-Dimethylhydrazin führt zu einem neuartigen Bor-Stickstoff-Selen-Heterocyclus (9, 10).
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19731060335
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    Die Struktur von 3-(Diphenylhydroxymethyl)-3H-azepin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1033-1037 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Structure of 3-(Diphenylhydroxymethyl)-3H-azepineThe structure of a compound C19H17NO formed by reaction of N-alkoxycarbonylazepines with phenyl lithium has been determined by X-ray technique using direct methods. The compound was identified as 3-(diphenylhydroxymethyl)-3H-azepine. The boat-shaped sevenmembered ring with structural angles α = 31° and β = 55° has the substituent in equatorial position.
    Notes: Die Struktur des Reaktionsproduktes C19H17NO aus N-Alkoxycarbonylazepinen und Phenyllithium wurde röntgenographisch durch Anwendung direkter Methoden bestimmt. Die Verbindung wurde als 3-(Diphenylhydroxymethyl)-3H-azepin identifiziert. Der bootförmige Siebenring mit Strukturwinkel von α = 31° und β = 55° trägt den Substituenten in äquatorialer Position.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060338
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    Autoxidation und Wasserstoffperoxid-Oxidation von 2,4,6-Triphenyl-λ3-phosphorin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1001-1011 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Autoxidation and Hydrogen Peroxide Oxidation of 2,4,6-Triphenyl-λ3-phosphorin2,4,6-Triphenyl-λ3-phosphorin (1) is slowly oxidized in benzene solution by dissolved oxygen. Two crystalline oxidation products were isolated. The structure of the lower melting substance is 4,4′0-dioxybis(1-hydroxy-1-oxo-2,4,6-triphenyl-λ5-1-phospha-2,5-cyclohexadiene) (2). Alkylation with triethyloxonium tetrafluoroborate leads to three stereoisomeric phosphinates 4E,E, 4E,Z, 4Z,Z, which by reduction with zinc in acetic acid yield two stereoisomeric ethyl hydroxyphosphinates 5E and Z. Steric assignment was made on the basis of the 1H n. m. r. data.Hydrogen peroxide oxidation of 1 yields 1-hydroxy-1-oxo-2,4,6-triphenyl-λ5-1-phospha-2,4- cyclohexadiene (3). Treatment with triethyloxonium tetrafluoroborate yields 1, 1-diethoxy-2,4,6-triphenyl-λ5-phosphorin (6) which was also prepared by another synthetic route and 1-ethoxy-6-ethyl-1-oxo-2,4,6-triphenyl-λ5-1-phospha-2,4-cyclohexadiene (13).
    Notes: 2,4,6-Triphenyl-λ3-phosphorin (1) wird in Benzol langsam durch den darin gelösten Luft-sauerstoff oxidiert. Zwei kristallisierte Oxidationsprodukte wurden isoliert. Die tieferschmelzende Verbindung ist 4,4′-Dioxybis(1-hydroxy-1-oxo-2,4,6-triphenyl-λ5-1-phospha-2,5-cyclohexadien) (2). Alkylierung mit Triathyloxonium-tetrafluoroborat liefert die drei stereoisomeren Phosphinsäureester 4E,E, 4E,Z, und 4Z,Z, deren Spaltung mit Zink und Eisessig zwei stereoisomere Hydroxyphosphinsäure-äthylester 5 E und Z ergibt. Die sterische Zu-ordnung gelang mit Hilfe der 1H-NMR-Spektren.Wasserstoffperoxid-Oxidation von 1 liefert 1-Hydroxy-1-oxo-2,4,6-triphenyl-λ5-1-phospha-2,4-cyclohexadiene (3). Mit Triäthyloxonium-tetrafluoroborat entsteht das auch auf anderem Wege aus 1 zugängliche 1,1 -Diäthoxy-2,4,6-triphenyl-λ5-phosphorin (6) neben 1-Äthoxy-6-äthyl-1-oxo-2,4,6-triphenyl-λ5-1-phospha-2,4-cyclohexadien (13).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060334
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    Berichtigung (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1054-1054 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060344
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    Masthead (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060401
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  • 180
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    Eine neue Synthese von Spirohex-4-en (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1076-1082 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis of Spirohex-4-eneSpirohex-4-ene (3) is obtained on a preparative scale by Corey-Winter elimination of 2. The n.m.r. data of 3 are compared with those of 3,3-dimethylcyclobutene (13) and cyclobutene.
    Notes: Spirohex-4-en (3) läßt sich in präparativem Maßstab durch Corey-Winter-Eliminierung aus 2 darstellen. Die NMR-Daten von 3, 3,3-Dimethylcyclobuten (13) und Cyclobuten werden vergleichend diskutiert.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060405
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  • 181
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    Heterocyclische Dicarbonsäureester, II. Zur Reaktion von 2,3-Bis(methoxycarbonyl)-4,5-dihydrofuranen mit Hydrazin und 1,2,3,6-Tetrahydropyridazin.  -  Synthese von 3-Hydroxy-4-(2-hydroxyalkyl)-5-pyrazolcarbonsäure-Derivaten (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1099-1106 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Dicarboxylic Acid Esters, II. Reaction of 2,3-Bis(methoxycarbonyl)-4,5-dihydrofurans with Hydrazine and 1,2,3,6-Tetrahydropyridazine.  -  Synthesis of 3-Hydroxy-4-(2-hydroxyalkyl)-5-pyrazolcarboxylic Acid DerivativesIn contrast to the 5,6-dihydro-4H-pyran and furan dicarboxylic acid esters 1 and 4, 2,3-bis-(methoxycarbonyl)-4,5-dihydrofurans 10a-c upon treatment with hydrazine do not yield the dihydrazides but undergo ring cleavage to the 3-hydroxy-4-(2-hydroxyalkyl)-5-pyrazolecarboxylic acid hydrazides 11a-c. Under mild conditions the intermediate ester 12a can be isolated. 12a as well as 11a, c can be hydrolyzed to the carboxylic acids 14a, b. Acyllactone rearrangement of the α-alkoxalyllactones 9a, d with hydrazine also yields the esters 12a, b. I.r. and n.m.r. data are discussed.
    Notes: Bei der Behandlung der 2,3-Bis(methoxycarbonyl)-4,5-dihydrofurane 10a-c mit überschüssigem Hydrazinhydrat entstehen, im Gegensatz zum Verhalten der analogen 5,6-Dihydro-4H-pyran- und Furandicarbonsäureester 1 und 4, nicht die entsprechenden Dihydrazide, sondern es tritt Ringöffnung zu den 3-Hydroxy-4-(2-hydroxyalky)-5-pyrazolcarbonsäure-hydraziden 11a-c ein. Unter schonenden Bedingungen läßt sich der 5-Pyrazolcarbonsäureester 12a isolieren. Sowohl 12a als auch 11a, c lassen sich zu den Carbonsäuren 14a, b verseifen. Die Ester 12a, b entstehen ebenfalls in einer Acyllacton-Umlagerung der α-Alkoxalyl-lactone 9a, d mit Hydrazin. Die IR- und NMR-Daten der dargestellten Verbindungen werden diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060407
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  • 182
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    Das System Azepin-Benzolimin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 970-983 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The System Azepine-Benzene imineExtended Hückel calculations are utilized in a discussion of: (a) the equilibrium position of the valence isomerization of 1N-azepine-benzene-1,2-imine, (b) the strenght of the benzeneimine σ bond involved in the isomerization, and (c) the influence of electron accepting groups at the nitrogen atom on the equilibrium position and azepine stability.
    Notes: Mit Hilfe der erweiterten Hückel-Methode werden a) die Gleichgewichtslage der Valenz-isomerisierung 1H-Azepin-Benzol-1,2-imin, b) die Stärke der an dieser Isomerisierung beteiligten σ-Bindung im Benzolimin und c) der Einfluß von Akzeptoren am Stickstoff auf das Gleichgewicht und auf die Stabilität des Azepins diskutiert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060331
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  • 183
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    Protonenresonanz-Spektroskopie ungesättigter Ringsysteme, XVIIIXVII. Mitteil.: D. Cremer und H. Günther, Liebigs Ann. Chem. 763, 87 (1972). Ein Benzolimin-1H-Azepin-Gleichgewicht (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 984-995 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Proton Resonance Spectroscopy of Unsaturated Ringsystems, XVIII.XVII. Mitteil.: D. Cremer und H. Günther, Liebigs Ann. Chem. 763, 87 (1972) A Benzeneimine-1 H-Azepine EquilibriumThe temperature dependence of the 1H n.m.r. spectrum of 4,5-bis(methoxycarbonyl)-3,6-diphenyl-1-p-tosyl-1H-azepine (11) is described. The results are interpreted on the basis of a benzeneimine-1H-azepine valence tautomerism (equilibrium distribution at room temperature ca. 3 : 97).
    Notes: Es wird über die Temperaturabhängigkeit des 1H-NMR-Spektrums von 4,5-Bis(methoxycarbonyl)-3,6-diphenyl-1 -p-tosyl-1H-azepin (11) berichtet. Die Befunde werden im Sinne einer Benzolimin-1H-Azepin-Valenztautomerie (Gleichgewichts-Verteilung bei Raumtemperatur ca. 3 : 97) interpretiert.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060332
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  • 184
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    Asymmetrische Synthesen mit 2-(Trifluormethyl)-3-oxazolin-5-onen, III. Synthese von N-Pivaloyl-L-tert-leucyl-L-valin, einem Acylpeptid mit hoher Gruppenhäufung (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1019-1022 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Syntheses with 2-(Trifluoromethyl)-3-oxazolin-5-ones, IIIThe reaction of 2-(trifluoromethyl)-3-oxazolin-5-ones with chiral α-aminoacid esters proceeds with high asymmetric induction1,2). It allows the synthesis of sterically hindered L-L (or D-D) dipeptide derivatives starting from the racematc of the N-terminal amino acid. The method is demonstrated with N-pivaloyl-L-tert-leucyl-L-valine (5), which is derived from oxazolinone 1 in 66% overall yield.
    Notes: Die bei der Umsetzung von 2-(Trifluormethyl)-3-oxazolin-5-onen mit chiralen α-Amino-säure-estern auftretende hohe asymmetrische Induktion1,2) erlaubt die Synthese sterisch gehinderter L-L(oder D-D)-Dipeptid-Derivate ausgehend vom Racemat der aminoendständigen Aminosäure. Die Methode wird am Beispiel des N-Pivaloyl-L-tert-leucyl-L-valins (5) demonstriert, das aus Oxazolinon 1 in einer Gesamtausbeute von 66% erhältlich ist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060336
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  • 185
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    Notiz zur Reaktion von α-Bromketonen mit Pyridinbasen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1041-1046 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060340
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  • 186
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    Beiträge zur Chemie des Hydrazins und seiner Derivate, XL. Notiz über ein neues, einfaches Verfahren zur Darstellung von Tetramethylhydrazin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1052-1053 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060343
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  • 187
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    (α-Methoxybenzyliden)triphenylphosphoran und (1-Methoxyäthyliden)triphenylphosphoran (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1062-1068 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (α-Methoxybenzylidene)triphenylphosphorane and (1-Methoxyethylidene)triphenylphosphorane(α-Methoxybenzylidene)triphenylphosphorane (2a) and (l-Methoxyethylidene)triphenylphosphorane (2b) have been prepared from the corresponding phosphonium salts. While 2a reacts with benzaldehyde to form α-methoxystilbene (3, 4) and triphenylphosphine oxide by means of the Wittig-reaction, the expected olefin could not be found in the analogous reaction of 2b. Instead of that, however, α-methoxypropiophenone (10) and triphenylphosphine are formed.  -  α,α′-Dimethoxystilbene (6a, 7a) and triphenylphosphine result from the thermal decomposition of 2a.
    Notes: (α-Methoxybenzyliden)triphenylphosphoran (2a) und (l-Methoxyäthyliden)triphenylphosphoran (2b) wurden aus den entsprechenden Phosphoniumsalzen dargestellt. Während 2a mit Benzaldehyd im Sinne der Wittig-Reaktion zu α-Methoxystilben (3, 4) und Triphenylphosphinoxid reagiert, wurde bei der gleichen Reaktion mit 2b das erwartete Olefin nicht gefunden, statt dessen jedoch α-Methoxypropiophenon (10) und Triphenylphosphin.  -  Die thermische Zersetzung von 2a führt zu α,α′-Dimethoxystilben (6a, 7a) und Triphenylphosphin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060403
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  • 188
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    Die Kristall- und Molekülstruktur von N3S3F3 (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1069-1075 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal and Molecular Structure of N3S3F3The crystal structure of N3S3F3 has been determined from single crystal X-ray data. The molecule forms a slightly puckered six-membered (S—N)3 ring with axial fluorine atoms. In contrast to N4S4F4 it has no alternating single and double bonds in the ring. The S—N bond lengths were found to be 1.587 (3) and 1.598 (3) Å, the S—F bond lengths to be 1.610 (3) Å. N3S3F3 crystallizes in the rhombohedral space group R3-C3i2.
    Notes: Die Struktur von N3S3F3 wurde röntgenographisch aus Diffraktometer-Einkristalldaten bestimmt. Das Molekül bildet einen leicht gewellten (S—N)3-Sechsring mit axialer Stellung der Fluoratome. Es hat im Gegensatz zum N4S4F4 keine alternierenden Doppel- und Einfach-bindungen im Ring. Die S—N-Bindungslängen betragen 1.587 (3) und 1.598 (3) Å, die S—F-Abstände 1.610 (3) Å. N3S3F3 kristallisiert rhomboedrisch in der Raumgruppe R3-C3i2 mit den (hexagonalen) Gitterkonstanten a = 10.238 (8) Å und c = 9.535 (7) Å.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060404
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  • 189
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    Kernresonanzspektroskopische Untersuchungen an Bor-Verbindungen, V. 1lB- und 14N-Kernresonanzmessungen an Alkoxy-, Alkylthio- und 1-Pyrrolylboranen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1145-1164 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nuclear Magnetic Resonance Studies on Boron Compounds, V. 11B and 14N N.M.R. Measurements of Alkoxy-, Alkylthio- and 1-Pyrrolylboranesδ11B and δ14N data for amino(alkoxy)- and amino(alkylthio)boranes as well as for a series of 1-pyrrolylboranes and related compounds are discussed. The δ14N data can be interpreted in terms of donation of the nitrogens free pair of electrons to the boron atoms as well as by the influence of inductive and steric effects, provided that only comparable series of compounds are discussed.
    Notes: Die chemischen Verschiebungen δ11B und δ14N für Amino(alkoxy)- und Amino(alkylthio)-borane sowie für eine Reihe von 1-Pyrrolylboranen und verwandten Verbindungen werden diskutiert. Die beobachteten δ14N-Werte erlauben Aussagen über die relative Beanspruchung des freien Elektronenpaares der Stickstoffatome durch das Boratom sowie über den Einfluß induktiver und sterischer Effekte bei vergleichbaren Verbindungsreihen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060413
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  • 190
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    Pilzinhaltsstoffe, 23. Stereospezifische Synthese der 10-Methyl-10-desmethoxycarbonyl-hemisecalonsäure A (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1198-1220 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Natural Products from Fungi, 23. Stereospecific Synthesis of 10-Methyl-10-desmethoxycarbonyl-hemisecalonic Acid AThe xanthone dienone 3b was obtained by synthesis and oxidative condensation of the tetrahydroxybenzophenone 2b. 3b could be transformed into 10-methyl-10-desmethoxy-carbonyl-hemisecalonic acid A (4) by stereoselective reduction. 4 corresponds to one half of the ergochrome secalonic acid A (1) molecule with respect to its configuration at the three centers of chirality and differs from it only by exchange of the CO2CH3 group with methyl. In connection with this total synthesis an investigation was carried out on the formation and stereochemistry of transformation products of the xanthone dienones 3a and b, as for instance also the seco-xanthone 24, which is structurally related to the ergot pigment ergoxanthin (30).
    Notes: Durch Synthese und oxidative Kondensation des Tetrahydroxybenzophenons 2b wurde das Xanthon-Dienon 3b gewonnen. Dieses konnte durch stereoselektive Reduktion in 10-Methyl-10-desmethoxycarbonyl-hemisecalonsäure A (4) übergeführt werden. 4 stimmt in der Konfiguration an seinen drei Chiralitätszentren mit einer Molekülhälfte des Ergochroms Secalon-säure A (1) überein und unterscheidet sich davon nur durch den Austausch der CO2CH3-Gruppe gegen Methyl. Tm Rahmen dieser Totalsynthese wurden Bildung und Stereochemie von Umwandlungsprodukten der Xanthon-Dienone 3a und b, wie z. B. auch des mit dem Mutterkorn-Farbstoff Ergoxanthin (30) strukturverwandten seco-Xanthons 24, untersucht.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060417
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  • 191
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    Die 5′-Carboxylgruppe als Schutzfunktion bei Nucleosidumwandlungen. Synthese von 2′-Desoxyadenosin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1256-1261 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Protective Function of the 5′-Carboxy Group in Nucleoside Transformations. Synthesis of 2′-DeoxyadenosineThe nearly quantitative transformation of 2′,3′-O-isopropylidenadenosine (1) to adenosine-5′-carboxylates 2b, c and the specific reduction of the 5′-alkoxycarbonyl group to the 5′-hydroxymethyl group under certain conditions renders the carboxy group useful as protective agent, the effect of which can be superior to the common protection of the 5′-hydroxymethyl group of nucleosides. This is illustrated in the synthesis of 8-bromo-2′-O-tosyladenosine (8). 8 is an important intermediate for the synthesis of 2′-deoxyadenosine (9).
    Notes: Die nahezu quantitative Umwandlung von 2′,3′-O-Isopropylidenadenosin (1) in die Adenosin-5′-carbonsäureester 2b, c und die unter bestimmten Voraussetzungen mögliche spezifische Reduktion der 5′-Alkoxycarbonylgruppe zur 5′-Hydroxymethylgruppe macht die Carboxylgruppe zu einer Schutzfunktion eigener Art, die dem gebräuchlichen Schutz der 5′-Hydroxymethylgruppe überlegen sein kann. Dies wird am Beispiel der Synthese von 8-Brom-2′-O-tosyladenosin (8) gezeigt. 8 ist eine wichtige Zwischenstufe zur Synthese von 2′-Desoxy-adenosin (9).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060422
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  • 192
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    Übergangsmetall-Carben-Komplexe, LIV. Der Pentacarbonyl(phenylcarben)chrom(0)-Rest als Amino-Schutzgruppe für Peptid-Synthesen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1277-1284 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Carbene Complexes, LV. Pentacarbonyl(phenylcarbene)chromium(0) as an Amino-Protecting Group in Peptide SynthesesAminolysis of pentacarbonyl[methoxy(phenyl)carbene]chromium(0) with aminoacid esters L-Phe-OMe, L-Pro-OMe, and L-Ala-OMe yields the corresponding N-carbene complexes 1-3 from pentacarbonyl(phenylcarbene)chromium(0) and the aminoacid esters. In the case of the L-Ala-OMe derivative the use of pentacarbonyl(phenylcarbene)chromium(0) as aminoprotecting group in peptide synthesis is studied. After alkaline hydrolysis of the methyl ester, reaction with L-Ala-OMe using the NHS/DCCD method gives the dipeptide derivative pentacarbonyl(phenylcarbene-L-Ala-L-Ala-OMe)chromium(0) (5), which yields analogously the tripeptide derivative pentacarbonyl(phenylcarbene-L-Ala-L-Ala-L-Ala-OMe)chromium(0) (6). 1H n.m.r., i.r. and mass spectra of the new compounds are discussed. The protecting group is cleaved off with trifluoroacetic acid at 20°C.
    Notes: Die Aminolyse von Pentacarbonyl[methoxy(phenyl)carben]chrom(0) mit den Aminosäureestern L-Phe-OMe, L-Pro-OMe und L-Ala-oMe liefert die entsprechenden N-Carbenkomplexe 1-3 aus Pentacarbonyl(phenylcarben)chrom(0) und den L-Aminosäure-methylestern. Am Beispiel des L-Ala-OMe-Derivates wird die Verwendung des Pentacarbonyl(phenylcarben)chrom(0)-Restes als Amino-Schutzgruppe für Peptidsynthesen untersucht. Nach der alkalischen Verseifung des Methylesters führt die Umsetzung mit L-Ala-OMe nach der NHS/DCCD-Methode zum Dipeptid-Derivat Pentacarbonyl(phenylcarben-L-Ala-L-Ala-OMe)chrom(0) (5), das in analoger Reaktion Zum Tripeptid-Derivat Pentacarbonyl(phenylcarben-L-Ala-L-Ala-L-Ala-OMe)chrom(0) (6) umgesetzt wird. 1H-NMR-, IR- und Massenspektren der neuen Verbindungen werden diskutiert. Die Abspaltung der Schutzgruppe erfolgt durch Trifluoressigsäure bei 20°C.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060424
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  • 193
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    Asymmetrische Reduktionen, II. Reduktion von (Diphenylmethyl)alkylketonen mit Komplexen aus Lithiumalanat und cis-2,3-Pinandiol (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1312-1318 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetric Reductions, II. Reduction of Diphenylmethyl Alkyl Ketones by Complexes Prepared from Lithium Alanate and cis-2,3-PinanediolAsymmetric reductions of diphenylmethyl alkyl ketones can be achieved by reagents prepared from lithium alanate and cis-2,3-pinanediol. The optical yields depend on the structure of the ketones. The stereoselectivity of the reduction can be influenced substantially by introduction of a benzyloxy substituent into the chiral reagent.
    Notes: (Diphenylmethyl)alkylketone werden durch Komplexe aus Lithiumalanat und cis-2,3-Pinandiol asymmetrisch reduziert. Die optischen Ausbeuten sind von der Struktur des Ketons abhängig. Die Stereoselektivität der Reduktion ist durch die Einführung eines Benzyloxyrests in das chirale Reagens entscheidend zu beeinflussen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060429
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  • 194
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    Notiz zur Darstellung von Dichlormaleinsäureanhydrid aus Hexachlorbutadien (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1363-1364 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060434
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  • 195
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    Masthead (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060501
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  • 196
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    Konfiguration der wandernden Gruppe bei der Desaminierung von 2,3-Dimethylpentylamin und 2,2,3-Trimethylpentylamin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1376-1383 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereochemistry of Aliphatic Carbonium Ions, 6. Configuration of the Migrating Group in the Deamination of 2,3-Dimethylpentylamine and 2,2,3-TrimethylpentylamineThe deamination of (3S)-2,3-dimethylpentylamine (7) afforded, among isomeric alcohols, 4-methyl-2-hexanol (16) with 87-88 % retention of configuration of the migrating sec-butyl group. In contrast, the sec-butyl migration in the deamination of (S)-2,2,3-trimethylpentylamine (25) proceeded with 98% retention of configuration to give 2,4-dimethyl-2-hexanol (27). The smaller amount of retention observed with 7 is attributed to competing reaction paths leading to 16 via protonated cyclopropanes. For comparison, we studied the deamination of 1,1,2-trimethylbutylamine (23) and found 3.5% of a 1,2-hydrogen shift between tertiary carbon atoms.
    Notes: Die Desaminierung von (3S)-2,3-Dimethylpentylamin (7) lieferte neben isomeren Alkoholen 4-Methyl-2-hexanol (16) mit 87-88% Konfigurationserhaltung der wandernden sec-Butylgruppe. Im Gegensatz dazu verläuft die sec-Butylwanderung bei der Desaminierung von (S)-2,2,3-Trimethylpentylamin (25) zu 2,4-Dimethyl-2-hexanol (27) mit 98% Konfigurations-erhaltung. Die geringere Retention bei 7 wird auf die konkurrierende Bildung von 16 über protonierte Cyclopropane zurückgeführt. Zum Vergleich untersuchten wir die Desaminierung von 1,1,2-Trimethylbutylamin (23) und fanden 3.5% 1,2-Wasserstoffverschiebung zwischen tertiären C-Atomen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060503
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    Cyclische Acylimine und ihre Salze (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1423-1432 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclic Acylimines and Their SaltsHydroxylactames 1 and 2 react with strong proton acids or Lewis acids to form acylimonium salts 3 and 4. The spectroscopic properties of the latter are described. 3-Phenyl-1-isoindolone (7) is prepared from 3-acetoxy-3-phenyl-1-isoindolinone (8) by action of triethylamine.
    Notes: Die Umsetzung der Hydroxylactame 1 und 2 mit starken Protonen- oder Lewis-Säuren führt zu Acylimoniumsalzen 3 und 4, deren spektroskopische Eigenschaften beschrieben werden. 3-Phenyl-1-isoindolon (7) entsteht aus 3-Acetoxy-3-phenyl- 1-isoindolinon (8) und Triäthylamin bei Raumtemperatur.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060508
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  • 198
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    Nucleoside, IX. Synthese und Eigenschaften von Lumazin-nucleosiden  -  Strukturanaloga des Uridins und Thymidins (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1401-1417 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nucleosides, IX. Synthesis and Properties of Lumazine Nucleosides  -  Structural Analogs of Uridine and ThymidineGlycosidation reactions of lumazine (1) and its 6,7-dimethyl (2) and 6,7-diphenyl derivative (3) with 1-halo- and 1-acyloxyribose and 2-deoxyribose derivatives respectively via the silyl method are described. The main reaction products turned out to be the lumazine-N-1 nucleosides. 1,3-Diglycosides are formed in minor amounts whereas in most cases the N-3 nucleosides are present only in trace quantities. The structures of the newly synthesized reaction products have been established by u. v. and n. m. r. spectra.
    Notes: Die Umsetzungen von Lumazin (1), seinem, 6,7-Dimethyl- (2) und 6,7-Diphenyl-Derivat (3) mit I-Halogen- bzw. 1-Acyloxyribose- und 2-Desoxyribose-Derivaten nach der Silyl-Methode werden beschrieben. Als Hauptprodukte werden die Lumazin- N-1-nucleoside gebildet. l,3-Diglycoside entstehen in untergeordnetem Maße, während die N-3-Nucleoside meist nur in Spuren nachweisbar sind. Die Strukturen der neu synthetisierten Produkte werden durch UV- und NMR-spektroskopische Untersuchungen gesichert.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060506
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  • 199
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    Perhalogenmethylthio-Heterocyclen, IV. Cl3-nFnCS-Substituierte Ketone und Diketone sowie deren Kondensation mit Phenylhydrazin (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1418-1422 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (Perhalomethylthio)heterocycles, IV. Cl3-nFnCS-Substituted Ketones and Diketones and their Condensation with PhenylhydrazineF3CSCl reacts with acetone or 2-butanone to give (trifluoromethylthio)acetone or 3-(trifluoromethylthio)-2-butanone (2a, b), respectively. The latter reacts with hydroxylamine hydrochloride to yield the corresponding oxime. Reaction of perhalomethanesulfenyl chlorides with 2,4-pentanedione leads to the formation of 3-substituted products (3a- c). These condense with phenylhydrazine to give 4-(perhalonmethylthio)-3,5-dimethyl-l-phenylpyrazoles (5a-c). Substitution of ethyl acetoacetate with Cl3-nFnCSCl takes place in 2-position (4b, c). The products obtained can be cyclized with phenylhydrazine to give 4-(perhalomethylthio)pyrazolones (6b, c).
    Notes: Die Umsetzung von F3CSCl mit Aceton bzw. 2-Butanon führt zu (Trifluormethylthio)aceton bzw. 3-(Trifluormethylthio)-2-butanon (2a, b). Letzteres reagiert mit Hydroxylamin-hydrochlorid zum entsprechenden Oxim. Perhalogenmethansulfenylchloride liefern mit 2,4-Pentandion in 3-Stellung Cl3-nFnCS-substituierte Produkte (3a- c). Diese kondensieren mit Phenylhydrazin zu 4-(Perhalogenmethylthio)-3,5-dimethyl-phenylpyrazolen (5a-c). Die Substitution von Acetessigsäure-äthylester mit Cl3-nFnCSCl erfolgt in 2-Stellung (4b, c). Die erhaltenen Produkte lassen sich mit Phenylhydrazin zu 4-(Perhalogenmethylthilo)-pyrazolonen (6b, c) cyclisieren.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060507
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  • 200
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    Stabile Methylnickelverbindungen, II. Methyl(trimethylphosphin)nickel-hydroxid und verwandte Verbindungen (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1433-1452 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stable Methylnickel Compounds, II. Methyl(trimethylphosphine)nickel Hydroxide and Related CompoundsMethods of preparation and properties of methylnickel dimers [LNi(CH3)X]2 (L = (CH3)3P, X = OH, OCH3, OC2H5, OSi(CH3)3, OC6H5, OC6H4CH3-(p), O2CH, O2CCH3, Cl) are presented. The positions of equilibria of cis and trans isomers are determined from their low temperature 1H n.m.r. spectra. Mixed bridged complexes [LNi(CH3)X]. [LNi(CH3)Y] (L = (CH3)3P, X = OCH3, Y = OH, OC2H5, OC6H5) only occur in the cis configuration. Addition of trimethylphosphine ligands affords monomers L2Ni(CH3)X (L = (CH3)3P, X = OC6H5, OC6H4CH3-(p), O2CCH3, Cl).
    Notes: Es werden Darstellung und Eigenschaften zweikerniger Methylnickelverbindungen [LNi(CH3)X]2 (L = (CH3)3P, X = OH, OCH3, OC2H5, OSi(CH3)3, OC6H5, OC6H4CH3-(p), O2CH, O2CCH3, Cl) beschrieben. Aus den 1H-NMR-Spektren bei tiefen Temperaturen kann die Lage der Gleichgewichte zwischen cis- und trans-Formen bestimmt werden. Gemischt verbrückte Komplexe [LNi(CH3)X]. [LNi(CH3)Y] (L = (CH3)3P, X = OCH3, Y = OH, OC2H5, OC6H5) werden nur in der cis-Konfiguration beobachtet. Mit Trimethylphosphin werden aus den zweikernigen Titelverbindungen die monomeren Komplexe L2Ni(CH3)X (L = (CH3)3P, X = OC6H5, OC6H4CH3-(p), O2CCH3, Cl) gebildet.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060509
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