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  • 1995-1999
  • 1975-1979  (749)
  • 1920-1924
  • 1977  (749)
  • Organic Chemistry  (688)
  • Rat
  • 1
    Electronic Resource
    Electronic Resource
    Das Anastomosengeschwür am operierten Magen (1977)
    Springer
    Langenbeck's archives of surgery 343 (1977), S. 133-151 
    Details
    ISSN: 1435-2451
    Keywords: Peptic ulcer ; Anastomosis ; Duodenogastric reflux ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die vorliegende Studie gilt dem Anastomosengeschwür am operierten Magen. Diese schwerwiegende Komplikation entsteht nahezu ausschließlich nach Resektionsverfahren mit duodenaler Exklusion (Billroth II; Verlegung des Duodenum in den Nebenschluß). - An 54 männlichen Wistarratten wurden verschiedene Formen der duodenalen Exklusion mit und ohne duodenogastrischen Reflux durchgeführt. Die Ergebnisse unserer Untersuchungen zeigen, daß nach duodenaler Exklusionmit Reflux gesetzmäßig peptische Anastomosengeschwüre entstehen. Der kontinuierliche Reflux von Galle und Pankreassekret ist der ausschlaggebende ätiologische Faktor für die Ulcusentstehung im Grenzgebiet der Anastomose von Magen und Dünndarm. Stase im ausgeschalteten Zwölffingerdarm (Syndrom der zuführenden Schlinge) fördert die lcerogene Refluxwirkung. Fehlt der Pylorus, so potenzieren sich Reflux und Stase zur größten Ulcusfrequenz (〉 90%). Bei erhaltenem Pylorus ist die Geschwürsincidenz wesentlich geringer. Der duodenogastrische Reflux hemmt die meßbare Salzsäuresekretion signifikant (P 〈 0,01); Salzsäure spielt demnach für die Entstehung des experimentellen Anastomosengeschwürs der Ratte keine wesentliche Rolle. - Im Hinblick auf die Prophylaxe des Anastomosengeschwürs führen diese Erkenntnisse zu der Forderung, auf Operationsverfahren mit duodenaler Exklusion und Reflux (Billroth II) zu verzichten und das Operationsziel bei der Magenresektion auf die Wiederherstellung der orthograden MagenDarm-Passage zu richten.
    Notes: Summary Different types of duodenal by-pass operations with and without duodenogastric reflux were performed on 54 male Wistar rats. The results of our investigation show that following duodenal by-pass with reflux peptic anastomotic ulcer regularly occurs. The constant reflux of bile and pancreas juice is the most important aetiologic factor in the development of ulcer in the vicinity of the anastomosis between the stomach and small intestine. Stasis in the by-passed duodenum (afferent loop syndrome) promotes ulcerogenic action of reflux. In the absence of the pylorus the effects of ref lux and stasis potentiate, resulting in a high frequency of ulcer (〉 90 %). With intact pylorus the incidence is low. Duodenogastric reflux prevents hydrochloric acid secretion significantly (P 〈 0.01); hydrochloric acid thus plays a minor role in the development of experimental anastomotic ulcer of the rat. - In considering the prophylaxis against anastomotic ulcer, these findings support the claim of avoiding surgical techniques involving duodenal by-pass and reflux (Billroth II with short loop GE). Gastric resection should, therefore, aim at the reconstruction of the orthograde peristalsis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01262005
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  • 2
    Electronic Resource
    Electronic Resource
    Microridge cells in the larynx of the male white rat. Investigations by reflection scanning electron microscopy (1977)
    Springer
    European archives of oto-rhino-laryngology and head & neck 215 (1977), S. 1-9 
    Details
    ISSN: 1434-4726
    Keywords: Respiratory epithelium ; Larynx ; Microridge cells ; Rat ; Scanning electron microscopy ; Respiratorisches Epithel ; Kehlkopf ; Mikroleistenzelle ; Ratte ; Rasterelektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Das Kehlkopfepithel ausgewachsener männlicher Albinoratten wird rasterelektronenmikroskopisch untersucht. Zusätzlich zu den zilientragenden und zu den Mikrovillizellen, zu den Bürsten- und Becherzellen, welche insgesamt für das respiratorische Epithel charakteristisch sind, werden in bestimmten Abschnitten des Larynx die Mikroleisten- oder Labyrinthzellen beschrieben. Die freie Oberfläche typischer Labyrinthzellen ist durch ein System von sich verzweigenden Mikroleisten gekennzeichnet, die miteinander durch Querbrücken verbunden sind und in der Zellperipherie eine bevorzugte Parallelausrichtung zur Zellgrenze zeigen können. Der Durchmesser der Mikroleisten beträgt ca. 0,05–0,15 μm. Die Querverbindungen zwischen den Mikroleisten haben einen Durchmesser von ca. 0,01 μm. Der Raum zwischen zwei benachbarten Querbrücken variiert. Labyrinthzellen können außer Mikroleisten auch Mikrovilli zeigen und es gibt Übergänge zwischen den Mikroridge- und den Mikrovillizellen. Die bevorzugte Lokalisation der Mikroleistenzellen im Bereich der Glottis und des Aditus laryngis wird belegt. Die mögliche Funktion dieser Zellen und ihre Bedeutung für die Diagnostik pathologischer Schleimhautveränderungen wird diskutiert.
    Notes: Summary The laryngeal epithelium of male white rats is studied by reflection scanning electron microscopy (SEM). In addition to ciliated cells, microvilli cells, brush cells and goblet cells that are characteristic for normal respiratory epithelium the microridge or labyrinth cell can be seen in particular regions of the larynx. The apical surface of a typical labyrinth cell is characterized by a system of narrow standing microridges of about 0.05–0.15 μm in diameter and interconnecting microridges with a diameter of about 0.01 μm. The microridge system of a labyrinth cell originates from the fusion of densely standing microvilli. Between microridge cells and microvilli cells all transition forms can be observed. The preferable localiziation of the microridge cell in the larynx and its possible function is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00463186
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  • 3
    Electronic Resource
    Electronic Resource
    Rasterelektronenmikroskopische Studien zur Feinstruktur des Epiglottisepithels von Ratten (1977)
    Springer
    European archives of oto-rhino-laryngology and head & neck 217 (1977), S. 41-51 
    Details
    ISSN: 1434-4726
    Keywords: Respiratory epithelium ; Epiglottis ; Rat ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The epithelial surface of the epiglottis in adult male and female albino rats is studied by scanning electron microscopy. Prominent differences exist between the surface morphology as observed in the males and that observed in the females sacrificed in the estrus phase of the ovarial cycle. The differences are most pronounced in respect to the amount of secretory vesicles, microvilli- and microridge-cells and in respect to the observable number of desquamating cells. The existence and the importance of the microridge-cells are discussed. Special attention is also paid to the results indicating that at least some parts of the extrapulmonary airway epithelia act as possible target organs for sex hormones. Finally the importance of the observed differences is discussed for the correct interpretation of pathomorphological alterations in the extrapulmonary airway epithelia that have been observed under experimental conditions and during infections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00453889
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  • 4
    Electronic Resource
    Electronic Resource
    Cyclic nucleotide phosphodiesterases of human and rat gastric mucosa (1977)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 296 (1977), S. 187-190 
    Details
    ISSN: 1432-1912
    Keywords: Cyclic nucleotide phosphodiesterase ; Gastric mucosa ; Human ; Rat ; Inhibitors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cyclic adenosine-3′,5′-monophosphate (cAMP) phosphodiesterases (PDE) were partially purified from human and rat gastric mucosa. Drugs known to affect the cyclic nucleotide system and/or gastric secretion were tested for effects on the PDE-activities from both species. In rat gastric mucosa PDE-activity can be detected in the 100 000×g sediment (K m =8.3 μM; V max=3.2 nmoles cAMP hydrolyzed/mg protein x min) and the cytoplasma (K m =5.6 μM; V max=2.6 nmoles cAMP hydrolyzed/mg protein x min). The most effective inhibitors of the particle-bound activity are papaverine (K i =4 μM, non-competitive) and 3-isobutyl-1-methylxanthine (K i=14 μM, competitive). There was only a modest competitive inhibition by theophylline (K i =495 μM). PDE-activity in the cytoplasma was inhibited competitively by these three drugs (papaverine: K i =6.5 μM; 3-isobutyl-1-methylxanthine: K i =37 μM; theophylline: K i =152 μM. In human gastric mucosa PDE-activity can be detected in the particular fraction (K m =23.9 μM; V max=1.2 nmoles cAMP hydrolyzed/mg protein x min), and the soluble fraction (K m =12.1 μM; V max=2.4 nmoles cAMP hydrolyzed/mg protein x min). PDE-activity in the 100 000×g sediment was inhibited by papaverine (K i =5.6 μM, non-competitive), 3-isobutyl-1-methylxanthine (K i =16 μM, non-competitive), theophylline (K i =165 μM, non-competitive), and N6-2′-O-dibutyryl-cAMP (K i =746 μM, competitive). Inhibition in the 100 000×g supernatant was noncompetitive with 3-isobutyl-1-methylxanthine (K i =7.1 μM and papaverine (K i =8.5 μM), but competitive with N6-2′-O-dibutyryl-cAMP (K i =170 μM), and theophylline (K i =225 μM). This study indicates that PDE-activities of the two species are qualitatively similar, but quantitative differences exist.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508473
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  • 5
    Electronic Resource
    Electronic Resource
    Cortical bone remodeling in normal rat (1977)
    Springer
    Calcified tissue international 23 (1977), S. 161-170 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Growth ; Rat ; Remodeling ; Tetracyclines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Cortical bone remodeling along the femur diaphysis was determined in normal female rats (Sprague-Dawley) with the tetracycline technique. Three segments on the cortical bone circumference (the anterolateral, the medial, and the posterior) were found to be most suitable for the study of the remodeling process. Oxytetracycline was administered at age 60 and 75 days, and groups of animals were killed at age 75, 85, 95, and 105 days. The accumulated endosteal growth during age 60 to 75 days in the anterolateral segment was found to increase uniformly in the distal direction along the femur diaphysis. A method is described where this accumulated endosteal growth is used. This method eliminates the use of calipers to determine the section level and makes it possible to study comparable sections even after varying periods of time. The proximal part of the diaphysis showed periosteal apposition in all three segments. The periosteal apposition turned into resorption in the distal part of the diaphysis in the anterolateral and medial segments, whereas the periosteal appsition increased in the posterior segment. The endosteal growth increased in the distal direction in the anterolateral and medial segments. Irregular OTC bands made measurements of endosteal remodeling in the posterior segment impossible. The cortical width decreased in the distal direction along the femoral shaft. Comparison between the different age groups is described and also the relation between the accumulated endosteal growth and the diameter of the medullary cavity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012782
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  • 6
    Electronic Resource
    Electronic Resource
    An analysis of response properties of spinal cord dorsal horn neurones to nonnoxious and noxious stimuli in the spinal rat (1977)
    Springer
    Experimental brain research 27 (1977), S. 15-33 
    Details
    ISSN: 1432-1106
    Keywords: Spinal cord ; Dorsal horn interneurones ; Pain mechanisms ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electrophysiological properties of neurones in the spinal cord dorsal horn were studied in decerebrated, immobilized spinal rats. Extracellular recordings were performed at the thoraco-lumbar junction level. Each track was systematically located by extracellular injection of pontamine sky blue. According to their responses to mechanical peripheral stimuli, cells were classified in four classes: Class 1 cells: Cells activated only by nonnoxious stimuli. They were divided into — 1A: hair movement and/or touch and 1B: hair movement and/or touch and pressure or pressure only. Class 2 cells: Cells driven by both nonnoxious and noxious stimuli, divided into — 2A: hair movement and/or touch, pressure, pinch and/or pin-prick, and 2B: pressure, pinch and/or pin-prick. Class 3 cells: Cells only activated by noxious stimuli (pinch and/or pin-prick). Class 4 cells: Cells responding to joint movement or pressure on deep tissues. Peripheral transcutaneous or sural nerve stimulation clearly showed that class 1 cells were activated only by A fiber input while 68% of classes 2 and 3 cells received A and C input. Histological examination indicated that cells driven only by noxious input were located either in the deepest part or in the marginal zone (lamina I) of the dorsal horn. Nevertheless, some lamina I cells were also driven by both nonnoxious and noxious stimuli. In addition, there is a great deal of overlap between class 1 and class 2 cells. This fact was confirmed by considering the wide distribution in the dorsal horn of cells receiving A and C input. However, spinal organization of the different classes of cells consists of a preferential distribution rather than a strict lamination. This study indicates that properties of dorsal horn interneurones in the rat have a high degree of similarity with those previously described in other species (cat and monkey).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234822
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  • 7
    Electronic Resource
    Electronic Resource
    The influence of the amygdala on the basal septum and preoptic area of the rat (1977)
    Springer
    Experimental brain research 29 (1977), S. 249-263 
    Details
    ISSN: 1432-1106
    Keywords: Preoptic area ; Basal septum ; Amygdala ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Extracellular microelectrode recordings were made from single neurones in the medial preoptic area and basal septum of normal female rats anaesthetised with urethane and the effects of stimulation of the ipsilateral amygdala (AMY) was tested. 1. Quiescent cells were excited with latencies between 4 and 〉 40 msec with the majority being between 10 and 27 msec. Variable latency, changing latency and recruitment were observed and suggest that many pathways are oligo- or polysynaptic. 2. A minority of spontaneously active units (20.6%) were excited with latencies between 5 and 36 msec. The predominant initial response was inhibition (67.1%). The remaining 12.3% of neurones did not respond. 3. A predominantly positive complex field potential was associated with excitation, particularly of quiescent neurones. 4. Inhibitory responses were classified according to duration (short: 20–60 msec; long: 100–400 msec). All responses contained an inhibitory component. Responses were further described on the basis of presence and rhythmicity of post-inhibitory excitation. 5. The majority of action potentials evoked from quiescent neurones were of small amplitude (80–150 μV) and occurred in small groups. These characteristics and their occurrence at the onset of inhibition are consistent with the view that all or a proportion of them may be generated by inhibitory interneurones. 6. Only minor differences were observed between response characteristics evoked by stimulation of the corticomedial or basolateral AMY indicating that differential effects of these regions on adenohypophysial hormone secretion are determined at the septopreoptic level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237045
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  • 8
    Electronic Resource
    Electronic Resource
    A cerebellar projection onto the pontine nuclei in the albino rat (1977)
    Springer
    Experimental brain research 30 (1977), S. 149-154 
    Details
    ISSN: 1432-1106
    Keywords: Dentate and interpositus nuclei ; Pontine gray ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following removal of a significant part of the dentate nucleus and most of the interpositus nucleus in the rat cerebellum degenerated cerebellopontine fibres are shown to end in three fairly restricted regions in the contralateral pontine gray: in the paramedian position, in the middle and in the lateral third. The three regions are arranged in rostro-caudal longitudinal columns in the caudal three-quarters of the pons and these columns are continuous with one another by regions of scattered degeneration. The fibres appear to end in relation to distal dendrites of the pontine cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237866
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  • 9
    Electronic Resource
    Electronic Resource
    Ultrastructural responses of the hypoglossal nucleus to the presence in the tongue of botulinum toxin, a quantitative study (1977)
    Springer
    Experimental brain research 30 (1977), S. 313-321 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Botulinum toxin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural effects of local injection of botulinum toxin into the left half of the tongue of the rat, were studied quantitatively 35 days postoperatively in the left hypoglossal nucleus. The results showed (1) a decrease in somatic and neuropil bouton numbers because of loss of boutons with symmetrical synapses and clear spherical synaptic vesicles, (2) a decrease in the numbers of dendrite profiles in the neuropil, (3) an increase in the proportion of dendrites and boutons with unusual inclusions, suggestive of profile retraction, (4) an increase in the proportion of profiles which were unusually electron-dense, (5) an increase in the amount of astrocyte, and a growth of astrocyte sheaths around bouton-free neurone surfaces, (6) the presence of occasional microglia, and (7) subastrocytic subsurface cisterns. Control rats injected with boiled toxin had no responses except (3) and (4) above, and then only to a modest extent, possibly due to mechanical damage of a few axons or terminals at the time of injection, or to insufficient inactivation of the toxin by boiling. The results were compared with those at 35 days after axotomy, and it was concluded that botulinum toxin, which interrupts neuromuscular transmission, elicits the same responses in the hypoglossal neurones, as does transection of the hypoglossal nerve, even though earlier studies had discovered no glial replication after botulinum toxin, in contrast to axotomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237258
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  • 10
    Electronic Resource
    Electronic Resource
    Cholinergic transmission in subcortical and cortical visual centers of rats: No evidence for the involvement of primary optic system (1977)
    Springer
    Experimental brain research 27 (1977), S. 211-219 
    Details
    ISSN: 1432-1106
    Keywords: Visual system ; Degeneration ; AChE ; Choline acetyltransferase ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of unilateral enucleation, ablation of the visual cortex or coagulation of the lateral geniculate nucleus (LGN) upon the activity of choline acetyltransferase (ChAc) and acetylcholinesterase (AChE) in different structures of the visual system of albino rats was studied. The localization and extent of the degeneration pattern were followed up by histological silver degeneration methods. Afferents from the retina project mainly contralaterally to the dorsal and ventral LGN, the pretectal region and the superior colliculus. Afferent fibres from the dorsal LGN enter the visual cortex in area 17 only. Neurons of this area project back ipsilaterally to the LGN and the superior colliculus (SC). No significant decrease in the activity of the cholinergic marker enzyme choline acetyltransferase could be observed under any of the experimental conditions; there was rather a tendency to increased activity in the subcortical centres. AChE as a less specific marker also exhibited no gross changes in activity in the lesioned animals. The results add more direct proof to pharmacological and physiological evidence that ACh is not involved in the synaptic transmission of the direct optic projections in rats, either at the subcortical or at the cortical level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237699
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  • 11
    Electronic Resource
    Electronic Resource
    Responses in the hypoglossal nucleus to delayed regeneration of the transected hypoglossal nerve, a quantitative ultrastructural study (1977)
    Springer
    Experimental brain research 29 (1977), S. 219-231 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Delayed regeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron micrographs of the left hypoglossal nucleus of adult male albino rats were quantitatively analyzed from 9–70 days after allowing the transected left hypoglossal nerve to regenerate after an 84 day delay. Delay was achieved by implanting the proximal stump into already innervated sternomastoid muscle, where no regeneration occurred. Regeneration was then allowed by denervating the sternomastoid. During the regenerative period the initially high number of abnormally electron dense perikarya and dendrites decreased to almost normal values, but no cell removal was seen. This suggested that the degenerate appearance of many profiles after prolonged prevention of regeneration, was reversible. The neuropil bouton and dendrite counts, and the numbers of synapsing boutons per dendrite, increased steadily to normal values from the low values of suppressed regeneration. Somatic bouton frequencies, even though already low, decreased further at 32 days, and later increased but not to normal values. The decrease at 32 days coincided with the loss of many subsurface cisterns, and dispersion of Nissl substance, all suggestive of chromatolysis. Later the subsurface cisterns and Nissl substance returned. It was suggested that the delay of complete recovery of somatic bouton frequencies might be because of lack of sensory information from the denervated muscle into which the hypoglossal nerve was regenerating, or because of abnormally low starting values for the recovery phase. Astrocyte (or, occasionally microglial) sheaths persisted along boutonfree perikaryal surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237043
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  • 12
    Electronic Resource
    Electronic Resource
    Cell death in the optic tectum of the developing rat (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 29-34 
    Details
    ISSN: 1432-0568
    Keywords: Optic tectum ; Rat ; Cell death
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The death of cells was studied by light microscopy in the optic tectum of normal, developing rats. Normal cell death in the tectum during development has previously been described in chickens but not in a mammal. The total period of cell death was from the 20th embryonic day through the 11th postnatal day. During this period the number of dying cells was comparatively small for the first 2 days, reached a peak at birth and then decreased over the next 11 days. In comparison to the number of surviving cells the number of dead cells in each section was small. The dead cells appeared to be randomly distributed in all layers of the optic tectum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315295
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  • 13
    Electronic Resource
    Electronic Resource
    The postnatal development of rat dentate gyrus and the effect of early thyroid hormone treatment (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 335-339 
    Details
    ISSN: 1432-0568
    Keywords: Autoradiography ; Hippocampus ; Neurogenesis ; Rat ; Thyroid hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The postnatal development of the dentate gyrus and the effect of 5 μg/day triiodothyronine treatment was examined by means of tritiated thymidine autoradiography. The polymorph layer of the dentate gyrus is a secondary germinal layer and forms cells for the granular layer. The cell formation in the dentate gyrus was found to be nearly completed on the 21st day, but development ended only in adulthood. Thyroid-hormone treatment did not affect significantly the postnatal cell formation of the dentate gyrus, but resulted in the appearance of a great number of pycnotic cells in the granular layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318935
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  • 14
    Electronic Resource
    Electronic Resource
    The surface ultrastructure of the habenular complex of the rat (1977)
    Springer
    Anatomy and embryology 152 (1977), S. 43-64 
    Details
    ISSN: 1432-0568
    Keywords: Habenula ; Ependyma ; Supraependymal cells ; Supraependymal axons ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The surface features of the ependymal lining of the habenular complex in rats, aged between three weeks and nine months, were studied by means of scanning and transmission electron microscopy. The ependyma of the medial habenular nucleus is heavily ciliated, the cilia obscuring underlying substructure in SEM — preparations. On the habenular commissure most cilia are arranged in tufts. Cilia are provided with segmental indentations and occasional apical thickenings. Vesicular protrusions of the ependymal cytoplasm into the ventricular lumen and the frequent occurrence of homogeneous supraependymal globules were interpreted as signs of ependymosecretory activity of nucl. hab. med. Supraependymal cells are most numerous on the anterior and superior surface of the habenular commissure. Cells presenting features identical to Kolmer (epiplexus) cells were identified on the ventricular surface of nucl. hab. med. in one specimen showing degenerative changes of undetermined aetiology in the habenular nuclei. It is therefore suggested that such cells need not necessarily be restricted to the choroid plexus. Supraependymal unmyelinated axons are particularly numerous on both nucl. hab. med. and commiss. hab. They make desmosome contacts (maculae adherentes) with the ependymal plasmalemma. Contacts presenting all features of typical synapses were not encountered. The vesicle population of the axonal profiles mainly comprises 35–50 nm translucent round vesicles besides small numbers of 60–100 nm dense-cored vesicles and large pleiomorphic vesicles. Most probably the axons belong to the well-established dense population of serotonergic axons in the dorsal part of the third ventricle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341434
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  • 15
    Electronic Resource
    Electronic Resource
    Absorption of horseradish peroxidase by the principal cells of the large intestines of postnatal developing rats (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 53-62 
    Details
    ISSN: 1432-0568
    Keywords: Large intestine ; Intestinal absorption ; Postnatal development ; Rat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The absorption of horseradish peroxidase in the rat large intestine during the postnatal developing period was investigated by cytochemical and ultrastructural methods. In the ceca and ascending colons from 4-, and 5-day-old rats, intraluminaly injected peroxidase became localised on microvilli, in the intracytoplasmic network of the apical tubules and small vacuoles (tubulo-vacuolar system), in the large supranuclear vacuole, in the Golgi apparatus, on the lateral and basal cell membranes of the surface principal cells, and also in the lumen of blood capillaries in the subjacent propria. On the other hand, the protein tracer was not seen in the large intestinal epithelial cells that lack tubulo-vacuolar systems and large supranuclear vacuoles within their cytoplasm. In the descending colons of rats of any postnatal age, the epithelial principal cells are devoid of these membrane systems, and exogenous peroxidase was not detected in the cytoplasm of the principal cells. It is assumed that at least the proximal portion of the large intestine in neonatal animals has the capacity to absorb macromolecular protein through those surface principal cells that have specialized intracellular membrane systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315297
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  • 16
    Electronic Resource
    Electronic Resource
    Influence of adrenalectomy on “Gomori-positive” substances in the hypothalamo-neurohypophysial system of rats heterozygous and homozygous for hypothalamic diabetes insipidus (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 81-89 
    Details
    ISSN: 1432-0568
    Keywords: Neurosecretion ; Adrenalectomy ; Diabetes insipidus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The influence of adrenalectomy on the amount of “Gomori-positive” neurosecretory material in the outer layer of the median eminence and in the supraoptico-hypophysial system was studied in normal Long-Evans rats and in Long-Evans rats heterozygous and homozygous for hypothalamic diabetes insipidus. In all non-adrenalectomized rats very few “Gomori-positive” granules were found in the outer median eminence layer. After adrenalectomy the amount of the granules increased markedly in normal Long-Evans rats and only slightly in Long-Evans rats heterozygous for diabetes insipidus. However, no augmentation of the granules occurred in homozygous diabetes insipidus rats. The amount of “Gomori-positive” substances demonstrable in the supraoptic and paraventricular nuclei, in the inner layer of the median eminence, and in the neural lobe of the hypophysis was less in rats heterozygous for diabetes insipidus than in normal Long-Evans rats and the smallest in homozygous diabetes insipidus rats. No differences in the amounts of the substances were observed between adrenalectomized and non-adrenalectomized animals. The findings suggest that the “Gomori-positive” granules occurring in the outer layer of the median eminence of adrenalectomized rats are of similar origin as those of the supraoptico-hypophysial system and represent a vasopressin-neurophysin-complex. The results support the concept that vasopressin is involved in the regulation of ACTH release.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315300
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  • 17
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    Electronic Resource
    The fine structure of the ependymal surface of the recessus infundibularis in the rat (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 241-265 
    Details
    ISSN: 1432-0568
    Keywords: Scanning E.M. ; Third ventricle ; Neurohypophysis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The surface of the recessus infundibularis of the third ventricle has been studied with the scanning and transmission technique in normal and experimental material. Surface specializations such as microvilli, craters and areas of discontinuous lining are described. Supraependymal cells and fibres have been found; some of these cells form wide-meshed networks. The supraependymal fibres may be regular or varicose; the former seem to perforate the ependyma. With the transmission electron microscope the supraependymal cells are divided into three categories: nerve cells, lymphocytes and “dense cells”. Two fibre populations are distinguished: thin profiles (nerve fibres) and thick profiles (nerve terminals). Axosomatic and axoaxonic synapses are described. Synapses between supraependymal fibres and ependyma cells have also been found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318929
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  • 18
    Electronic Resource
    Electronic Resource
    The accessory phrenic nerve in the rat (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 63-69 
    Details
    ISSN: 1432-0568
    Keywords: Rat ; Phrenic nerve ; Accessory phrenic nerve ; Diaphragmatic myotomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Reinnervation studies of the diaphragm led us to reinvestigate the normal anatomy of the phrenic nerve of the rat. The phrenic nerve originates from the cervical nerve roots C4 and C5. In 16 out of 19 normal rats an accessory phrenic nerve was observed receiving its segmental fibres from C6. The number of myelinated axons of the accessory phrenic nerve varied from 41 to 101 (mean: 64.3, i.e. about 15% of the average number of axons in the common phrenic nerve). The accessory phrenic nerve innervates the dorsal part of the costal and the lateral part of the crural region, whereas the remaining parts of the hemidiaphragm are supplied by the segments C4 and C5. There is no evidence for any additional contribution to the motor innervation of the diaphragm from intercostal nerves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315298
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  • 19
    Electronic Resource
    Electronic Resource
    The influence of protein-calorie malnutrition on the development of paranodal regions in spinal roots (1977)
    Springer
    Acta neuropathologica 40 (1977), S. 253-257 
    Details
    ISSN: 1432-0533
    Keywords: Protein-calorie malnutrition ; Rat ; Spinal root ; Paranodal region ; OTAN method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary During the early postnatal development of spinal roots in rats paranodal regions were often found, containing OTAN-positive inclusions in the Schwann cell cytoplasm. The presence of OTAN-positive paranodal regions showed variations in time, which were synchronous for ventral and dorsal roots. Dorsal roots, however, showed a more marked presence during development than ventral roots. Spinal roots of animals submitted to a 50% food restriction, were shown to contain more OTAN-positive paranodal regions than controls. This was true for ventral as well as dorsal roots. It is suggested that crowding of internodal segments could be one factor, determining the presence of paranodal, OTAN-positive material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691963
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  • 20
    Electronic Resource
    Electronic Resource
    Paranodal myelin retraction in protein deficient and normal rats (1977)
    Springer
    Acta neuropathologica 40 (1977), S. 249-252 
    Details
    ISSN: 1432-0533
    Keywords: Low-protein diet ; Rat ; Peripheral nerve ; Paranodal area ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Young rats, submitted to severe protein restriction were studied concerning the width of intermyelin gaps at the nodes of Ranvier in peripheral nerve fibres. The results gave no proof of increased paranodal myelin retraction in lumbar spinal roots or the sciatic nerves of low-protein rats. Malnourished rats as well as controls showed great interindividual differences as to the presence of nodes with wide inter-myelin gaps.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691962
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  • 21
    Electronic Resource
    Electronic Resource
    Plasma fluoride and enamel fluorosis (1977)
    Springer
    Calcified tissue international 22 (1977), S. 77-84 
    Details
    ISSN: 1432-0827
    Keywords: Fluoride ; Blood plasma ; Enamel mineralization ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract It is postulated that tissue fluid F concentrations are the primary determinants of fluoride effects on bones and developing teeth and that these concentrations are dependent on, or mirrored by, blood plasma F. It has earlier been shown that the plasma F levels are dependent on the dietary F supply as well as on skeletal F concentration. Fasting and post-ingestion or postinjection plasma F levels have been determined in rats on F doses that cause different degrees of enamel fluorosis. The results indicate that temporary peak values rather than elevated fasting values are responsible for the occurrence of enamel fluorosis and that the peak values must approach about 10 μM in order to block enamel formation by the ameloblasts. The diagnostic and prognostic importance of plasma F determinations is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010348
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  • 22
    Electronic Resource
    Electronic Resource
    Lamellar organisation in the rat hippocampus (1977)
    Springer
    Experimental brain research 28 (1977), S. 335-344 
    Details
    ISSN: 1432-1106
    Keywords: Hippocampus ; Rat ; Lamellae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A series of experiments was conducted in the urethane anaesthetised rat to determine the organisation of some hippocampal pathways in this species, using stimulating and recording microelectrodes to elicit and record population spikes. It was found that the mossy fibres, alvear fibres and perforant path were clearly arranged in a lamellar fashion. Lamellar organisation could not be demonstrated for the afferents in the stratum radiatum which include the Schaffer collaterals. It was concluded that hippocampal organisation in this species essentially resembles that in the rabbit and cat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235715
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  • 23
    Electronic Resource
    Electronic Resource
    An automated method for studying exploratory and stereotyped behaviour in rats (1977)
    Springer
    Psychopharmacology 52 (1977), S. 271-277 
    Details
    ISSN: 1432-2072
    Keywords: Rat ; Exploratory behaviour ; Stereotyped behaviour ; Hole-board ; dl-Amphetamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A technique is described for studying exploratory as well as stereotyped behaviour in rats using an automated hole-board. Both visual and automated recordings can be employed using the technique. Hole dipping is monitored automatically using an infra-red detector system. Repetitive patterns of hole-dipping are used as parameters of stereotyped behaviour while the more random patterns of hole-dipping are used as parameters of exploration. There was a high significant correlation between the records of hole-dipping behaviour as recorded visually and automatically. There was also a high significant correlation between the measures of repetitiveness/randomness of hole-dipping behaviour from automatic and visual recordings. The pattern and levels of hole-dipping conformed with expectations both as regards changes with time and with increasing doses of dl-amphetamine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426711
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  • 24
    Electronic Resource
    Electronic Resource
    Naloxone-induced or postwithdrawal abstinence signs in Δ9-Tetrahydrocannabinol-Tolerant rats (1977)
    Springer
    Psychopharmacology 55 (1977), S. 243-249 
    Details
    ISSN: 1432-2072
    Keywords: Abstinence syndrome ; Tolerance ; Physical dependence ; Rat ; THC ; Morphine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ten rats were injected s.c. with THC twice daily for 5 weeks in increasing doses. In the last 3 weeks they received 40 mg/kg THC in each administration. Ten control rats received the same amount of vehicle by the same route for the same period. The comparison of rectal temperatures of the first and fifteenth days showed that a very pronounced tolerance developed to the hypothermic effect of THC. The administration of naloxone on the 22nd and 31st days precipitated an opiatelike abstinence syndrome. The termination of the drug administration on the 35th day also produced a similar withdrawal syndrome. The most common signs of abstinence syndrome in THC-treated animals were teeth chattering, defecation, urination, dyspnea, and complete palpebral closure. Although the frequency of the incidence of the following signs were not high, they have been observed only in THC-treated animals: chewing, tremors on the face, escape behavior, jumping, eating of objects, biting of fingers, and sniffing. During abstinence, an increased locomotor activity was recorded by an activity-meter. Similarly, the total amount of excreted feces and urine was higher in the THC group than in the controls. Both abstinence scores and increased motility exhibited the peak in the 48th h of withdrawal. Some similarities between the effects of THC and morphine have been reviewed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00497855
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  • 25
    Electronic Resource
    Electronic Resource
    On the secretagogue effect of dibutyryl cyclic AMP in the rat exocrine pancreas (1977)
    Springer
    Pflügers Archiv 372 (1977), S. 69-76 
    Details
    ISSN: 1432-2013
    Keywords: Dibutyryl cyclic AMP ; Pancreas ; Rat ; Secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary DbcAMP≥0.1 mM induces the discharge of exportable enzymes from rat pancreas fragments incubated in vitro. This effect is qualitatively similar to the action of physiological secretagogues acting via hormone receptors: 1) it is accompanied by the appearance of exocytotic images at the acinar cell apex; 2) it is energy dependent but energy supply is low while that required for the carbamylcholine or caerulein response is high and can only be afforded by oxidative phosphorylation; 3) it is calcium dependent, but no alteration of inward or outward calcium movement can be observed; 4) it is altered by agents known to disrupt the microfilamentous microtubular system [41]. However, the secretory response to DbcAMP is quantitatively less than that obtained with hormonal stimuli. A damaging effect of DbcAMP on pancreatic acinar cells is ruled out on histological and biochemical grounds: there is no significant leakage of LDH; protein synthesis, 2-deoxy-d-glucose andl-leucine uptake are unaltered. The secretagogue effect of DbcAMP is reversible, dose-related and specific. It is not mediated by neuro-transmitter release or by interaction with their receptors. The evidence presented points to a direct interaction of DbcAMP on the pancreatic acinar cell and suggests the last step of the secretory cycle as the most probable site of action of the nucleotide derivative.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582208
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  • 26
    Electronic Resource
    Electronic Resource
    Relative organ blood flow in rats exposed to intermittent high altitude hypoxia (1977)
    Springer
    Pflügers Archiv 368 (1977), S. 111-115 
    Details
    ISSN: 1432-2013
    Keywords: Altitude ; Myocardium ; Regional blood flow ; Blood volume ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Circulating blood volume, cardiac output and relative organ perfusion changes were studied, using the Sapirstein method of86Rb tissue uptake, in male 75-day-old rats exposed to intermittent high altitude hypoxia (gradually up to 7000 m, 4 h daily, 5 days a week; the total number of exposures was 24). Intermittent hypobaric exposure caused a significant rise of the erythrocyte volume, whereas the plasma volume remained unchanged. The relative perfusion of the left and particularly of the right ventricular myocardium, as well as of the spleen, liver, lung, small intestine and skeletal muscle, was significantly higher. The cardiac output determined in other experimental animals similarly treated was significantly higher after 24 exposures to the intermittent high altitude hypoxia. We suggest that these changes are triggered by tissue hypoxia and a greater blood flow demand.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01063462
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    Electronic Resource
    Fever in rats after intravenousE. coli endotoxin administration (1977)
    Springer
    Pflügers Archiv 368 (1977), S. 125-128 
    Details
    ISSN: 1432-2013
    Keywords: Endotoxin ; Rat ; Fever ; Anti-endotoxin system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In conscious unrestrained rats, at an ambient temperature of 22°C, oesophageal temperature was measured and temperature effect of single and repeated intravenous injection ofE. coli endotoxin was examined. The first injection of endotoxin in a dose of 10.0 μg/rat did not change the rat body temperature. The second injection of this dose in the same animals repeated after 48 h produced fever. With following injections the fevers observed were less pronounced. The absence of fever after a single injection of endotoxin was accompanied by the rapid loss of pyretic activity of the rat plasma samples (bioassayed in rabbits). When fever was observed (48 h interval between endotoxin injections) the pyretic activity of the rat plasma remained unchanged for 90 min following endotoxin injection. It was concluded that after a single injection endotoxin is rapidly detoxified in the rat circulation while this process does not take place after the second endotoxin injection (48 h interval). The process of endotoxin detoxification can be depressed by the pretreatment with nitrogen mustard. Analysis of changes of skin temperature following endotoxin injections and the influence of aspirin on endotoxin-induced fever suggest that the fever observed was of central origin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01063464
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  • 28
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    Electronic Resource
    Biochemical and morphological changes in some organs of rats in nickel intoxication (1977)
    Springer
    Archives of toxicology 37 (1977), S. 159-164 
    Details
    ISSN: 1432-0738
    Keywords: Nickel ; Rat ; Toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zu verschiedenen Zeiten nach täglicher Zufuhr von Nickelsulfat an Ratten wurden Leber, Niere, Hoden und Herzmuskel auf biochemische und histologische Änderungen untersucht. Während sich in der Initialphase noch keine signifikanten Veränderungen nachweisen ließen, traten nach längerer Exposition deutliche enzymatische und histopathologische Veränderungen in allen vier untersuchten Organen auf. Das Ausmaß der Organläsionen zeigte einen direkten Zusammenhang mit der Behandlungsdauer.
    Notes: Abstract Biochemical and histological alterations in liver, kidney, testis and myocardium of albino rats were investigated at various intervals after daily administration of nickel sulphate. No significant changes were observed during the initial periods of the treatment, but longer exposures produced marked enzymatic and histopathological alterations in all the four organs examined. The severity of the histological lesions was found to be directly related to the duration of the treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00293867
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  • 29
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    Electronic Resource
    Levels of sulfhydryls and sulfhydryl-containing enzymes in brain, liver and testis of manganese treated rats (1977)
    Springer
    Archives of toxicology 37 (1977), S. 319-325 
    Details
    ISSN: 1432-0738
    Keywords: Sulfhydryls ; Enzymes ; Brain ; Liver ; Testis ; Manganese ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Wirkung von Mangan auf Sulfhydrylgruppen und SH-enthaltende Enzyme in Gehirn, Leber und Hoden von Ratten wurde untersucht. Mangan verminderte den Gehalt an Nicht-Eiweiß-SH und hemmte die Glucose-6-phosphatdehydrogenase sowie die Glutathionreduktase in diesen Geweben. In Gehirn, Leber und Hoden der Mn-behandelten Tiere war der Mn-Gehalt signifikant erhöht.
    Notes: Abstract The effect of manganese on sulfhydryls and sulfhydryl-containing enzymes in brain, liver and testis of rats was investigated. Manganese produced lowering in the contents of non-protein sulfhydryl groups and inhibited the activity of glucose-6-phosphate dehydrogenase and glutathione reductase in these tissues. The contents of the metal increased significantly in brain, liver and testis of manganese administered rats. The significance of these findings is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330824
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    Electronic Resource
    Zur Toxikologie von Carbromal (1977)
    Springer
    Archives of toxicology 37 (1977), S. 275-288 
    Details
    ISSN: 1432-0738
    Keywords: Carbromal ; Bromoethylbutyramide ; Ethylbutyrylurea ; Rat ; Pharmacokinetics ; Smooth muscle ; Carbromal ; Carbromid ; Äthylbutyrylharnstoff ; Ratte ; Pharmakokinetik ; glatter Muskel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Oral verabreichtes Carbromal und Carbromid wurden bei Ratten in Dosen unter 20 mg/kg rasch aus dem Magen-Darmtrakt aufgenommen, aus dem Dünndarm 5–8mal rascher als aus dem Magen. Die enterale Resorption von Carbromaldosen größer als 20 mg/kg verlief wesentlich langsamer. Dies ist hauptsächlich auf eine verzögerte Magenentleerung zurückzuführen. Sowohl Carbromal als auch Carbromid hemmten in vitro den Tonus und die durch Acetylcholin induzierte Kontraktion glatter Muskeln des Magenfundus. Carbromal und Carbromid fanden sich im Organismus in gleicher Konzentration in Serum, Gehirn und Skelettmuskulatur. Im Fettgewebe wurden dreimal höhere Werte gemessen. Die Konzentrationen beider Stoffe fallen in den untersuchten vier Organen mit der gleichen Geschwindigkeit wieder ab. Es lassen sich daher mit Hilfe der leicht zu messenden Serumkonzentrationen rasch die im Organismus verteilten Mengen beider Substanzen ermitteln. Intraperitoneal injizieŕtes Carbromal und Carbromid verlassen Serum und Gehirn mit einer Halbwertzeit von 3–4 h, Äthylbutyrylharnstoff mit einer Halbwertzeit von 5–7 h. Carbromal, Carbromid und Äthylbutyrylharnstoff werden von der Ratte rasch und nahezu vollständig metabolisiert. In Urin und Kot erschienen nur Spuren dieser Substanzen. Für eine Sekretion von Carbromal und seinen beiden Metaboliten in den Magen ergab sich kein Anhalt. Die Ergebnisse werden im Hinblick auf die akute Carbromalvergiftung beim Menschen diskutiert.
    Notes: Abstract Oral doses up to 20 mg/kg of carbromal and of bromoethylbutyramide were rapidly absorbed in the rat. Absorption from the stomach ligated at the pyloric end was 5–8-fold less than absorption of carbromal injected directly into the small intestine. Oral doses greater than 20 mg/kg of carbromal disappeared more slowly from the gastro-intestinal tract because gastric emptying was delayed. Both carbromal and bromoethylbutyramide were able to reduce the basal tone and the acetylcholine-induced contraction of isolated rat fundus strips. Carbromal and bromoethylbutyramide distributed evenly between serum, brain and skeletal muscle. Concentrations in adipose tissue were three times those in the other three tissues. Concentrations of both carbromal and of bromoethylbutyramide in all four tissues declined at the same rate. Thus, serum concentration of either compound may be used to estimate the total body content. Intraperitoneally injected carbromal, bromoethylbutyramide and ethylbutyrylurea disappeared from the brain and from the serum with a half-life of 3–4 h and 5–7 h, respectively. Traces only of unchanged carbromal, bromoethylbutyramide, or ethylbutyrylurea were excreted with urine or feces indicating rapid and extensive biotransformation of the three compounds in this species. No evidence was obtained of secretion of either carbromal or its two metabolites into the lumen of the stomach. The findings are discussed as to their relevance for acute carbromal poisoning in humans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330819
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    The effect of mercuric chloride on the excretion of two urinary enzymes in the rat (1977)
    Springer
    Archives of toxicology 37 (1977), S. 219-225 
    Details
    ISSN: 1432-0738
    Keywords: Inorganic mercury ; Renal enzyme excretion ; Chelating agents ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Wirkung von intravenös verabreichtem HgCl2 auf die renale Ausscheidung von alkalischer Phosphatase (AP) und Leucinaminopeptidase (LAP) wurde an Ratten untersucht. Am ersten Tag nach Hg-Injektion erfolgte ein Anstieg der Enzymausscheidung, der von einem Schwellenwert von 0.44 mg Hg/kg ausgehend eine lineare Abhängigkeit von der Hg-Dosis aufwies. Am zweiten Tag wurde ein statistisch signifikanter Effekt bereits nach 0.25 mg Hg/kg beobachtet. Nach Dosen von 0.75 mg Hg/kg oder mehr fand ein Abfall der Enzymaktivität unter die Kontrollwerte statt, der mehr als 4 Tage anhielt. Behandlung mit 2,3-Dimercaptopropansulfonat (DMPS) bewirkte eine Normalisierung der AP-Ausscheidung. Eine Wirkung auf die LAP-Exkretion wurde nur bei baldiger Verabreichung von DMPS beobachtet. Das gleiche gilt für den Effekt von DMPS auf die Hg-induzierte Letalität. Die Nützlichkeit einer LAP-Bestimmung im Urin zur Abschätzung einer Hg-Inkorporation wird diskutiert.
    Notes: Abstract The effect of intravenous injections of HgCl2 on the renal excretion of alkaline phosphatase (AP) and leucine aminopeptidase (LAP) was investigated in rats. On the first day after Hg enzyme excretion showed a linear rise with the Hg dose from a threshold value of 0.44 mg Hg/kg. On the second day a statistically significant effect was seen already after 0.25 mg Hg/kg. After doses of 0.75 mg/kg or more a decrease of enzyme activity below control values occurred which persisted for more than 4 days. Treatment with 2,3-dimercaptopropansulfonate (DMPS) brought about a normalization of AP excretion. An effect on LAP excretion was observed only with early treatment. The same holds for the effect of DMPS on Hg-induced lethality. The usefulness of a measurement of LAP excretion for estimating the exposure to inorganic mercury is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00355490
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    Neurobehavioral and systemic effects of longterm blood lead-elevation in rats (1977)
    Springer
    Archives of toxicology 37 (1977), S. 247-263 
    Details
    ISSN: 1432-0738
    Keywords: Lead in blood ; Longterm exposure ; Learning deficit ; Overreaction ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zur Erfassung neuropsychologischer Störungen nach ontogenetisch früher Bleiexposition wurde bei männlichen Wistar-Ratten pränatal über deren Mütter, neonatal über die Muttermilch und postnatal über Bleiazetathaltiges Futter (745 mg Pb/kg Futter) chronisch ein erhöhter Blutbleispiegel (PbB) eingestellt. In der Trächtigkeits-und Säugezeit stieg der PbB-Spiegel der Mütter von 24.2 auf 31.2 μg-% an, während derjenige der Nachkommen im Alter von ca. 16 Tagen 26.6 μg-% und im Alter von ca. 190 Tagen 28.5 μg-% betrug. PbB altersgleicher Kontrollen war stets 〈 6 μg-%. Im Alter zwischen 100 und 200 Tagen wurden 20 Bleitiere und 20 Kontrollen blind verschiedenen Verhaltensprüfungen unterzogen, und zwar einem Open Field-Test und einer visuellen Unterscheidungs-Lernaufgabe. Zwei Lernprobleme unterschiedlicher Schwierigkeit, Richtungs- und Größenunterscheidung, wurden benutzt. Im Open Field-Test waren die Bleitiere im Vergleich mit den Kontrollen signifikant unruhiger: Lokomotorische Aktivität, Aufrichten und Putzverhalten waren gesteigert. Die schwierige Größenunterscheidung erlernten nur die Kontrollen, während das leichte Problem, nämlich die Richtungsunterscheidung, von Kontroll- und Bleitieren gleich schnell erlernt wurde. Die beobachteten Bleiwirkungen, gesteigerte motorische Unruhe und Lernleistungshemmung, lassen sich als Indikatoren einer funktionellen Hirnschädigung deuten. Sie legen den Schluß nahe, daß die „Wirkschwelle” für neuropsychologische Störungen nach ontogenetisch frühzeitiger Bleieinwirkung bei der Ratte als unterhalb 35 μg/100 ml liegend angenommen werden muß.
    Notes: Abstract In order to assess neurobehavioral deficit subsequent to early low-level lead-exposure, Wistar-rats were prenatally Pb-exposed via their mothers, neonatally via their dams' milk, and later on via their diet containing lead acetate (745 mg Pb/kg diet). Blood-lead levels (PbB) of dams increased from 24.2–31.2 μg-% during pregnancy and suckling-periods, those of offsprings were 26.6 μg-% at about 16 days of age and 28.5 μg-% at about 190 days of age. Between 100 and 200 days of age 40 male offsprings were subjected to behavioral testing, namely an open field-test and a visual discrimination-learning task. Two learning-tasks of different complexity, i.e. orientation-and size-discrimination, were used. Data of 20 lead-treated animals were compared with those of 20 age-matched controls. In the open-field test lead-fed animals were significantly more restless than controls; an increase of ambulation, rearing and grooming was observed. In the difficult learning-task, i.e. size discrimination, only the controls did learn the problem, whereas only one of the lead-group did; there was, however, no difference between lead-and control-animals for the easy task, i.e. orientation-discrimination. The observed effects, namely overreaction in the open field and a deficit of visual discrimination learning, may be interpreted in terms of lead-induced CNS-dysfunction. They clearly suggest that the “no-response level” for neurobehavioral damage in the rat, subsequent to early lead-exposure, must be assumed to be lower than 35 μg/100ml.
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    URL: http://dx.doi.org/10.1007/BF00330817
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    Electronic Resource
    Intracellular histidine content of various tissues (brain, striated muscle and liver) in experimental chronic renal failure (1977)
    Springer
    Journal of molecular medicine 55 (1977), S. 583-585 
    Details
    ISSN: 1432-1440
    Keywords: Histidin ; Gehirn ; Skelettmuskel ; Leber ; Urämie ; Ratte ; Histidine ; Brain ; Striated muscle ; Liver ; Uremia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Intracellular histidine levels were determined in brain, striated muscle and liver of rats with chronic renal insufficiency (5/6-nephrectomy) and compared both with normal rats and food-restricted (pair-fed) animals. There was no difference in plasma histidine concentration of the three groups whereas in the brain of the uremic rats histidine was significantly increased. Since there existed no alteration of the cerebral histidine in the corresponding pair-fed group, the finding of a raised histidine level in the renal insufficient rats seems to be due to a specific uremic disorder caused by a cerebral disturbance in histidine metabolism.
    Notes: Zusammenfassung Bei chronisch niereninsuffizienten Ratten (5/6-Nephrektomie) wurden die intrazellulären Histidin-Konzentrationen verschiedener Organe (Gehirn, Skelettmuskel und Leber) bestimmt. Als Vergleichsgruppen dienten gesunde Kontroll-Ratten sowie sog. „pair-fed“ Ratten, die entsprechend den niereninsuffizienten Tieren eine verminderte Nahrungsmenge zu sich nahmen. Während sich in den untersuchten Gruppen die Plasma-Histidin-Konzentration nicht unterschied, war Histidin im Gehirn der chronisch niereninsuffizienten Tiere signifikant erhöht. Dieser Konzentrations-Anstieg dürfte als urämie-spezifisch anzusehen sein, da die entsprechend minderernährten Kontrolltiere keine Alteration zeigten. Als Ursache ist in erster Linie eine cerebrale Störung des Histidin-Metabolismus zu diskutieren.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01490512
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  • 34
    Electronic Resource
    Electronic Resource
    Enduring effects of morphine pellets revealed by conditioned taste aversion (1977)
    Springer
    Psychopharmacology 51 (1977), S. 279-283 
    Details
    ISSN: 1432-2072
    Keywords: Morphine ; Naloxone ; Abstinence signs ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Morphine pellets (75 mg) were implanted subcutaneously in albino rats. Three days later, following 24 h without water, these rats (Group MSN) were given access to a saccharin solution for 30 min, then injected with naloxone hydrochloride. The classical abstinence signs, including “wet dog shakes” and weight loss, were noted in these subjects, but not in controls given placebo pellets and/or saline injections. In addition, when given an opportunity to drink either saccharine solution or water 24 h later, Group MSN rats drank significantly less saccharin than any of the control groups. Similar drinking patterns were found even when naloxone injection was delayed as long as 3 weeks after pellet implantation, when none of the classical abstinence signs were seen and serum levels of morphine and its metabolites were 100 times lower according to radioimmunoassay. This simple and objective technique is thus more sensitive as a measure of prior morphine exposure than any of the commonly used indices. The continued utility of a dependent-nondependent dichotomy is also examined in light of these and other findings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00431636
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  • 35
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    Electronic Resource
    Deficits in passive-avoidance learning following atropine in the developing rat (1977)
    Springer
    Psychopharmacology 54 (1977), S. 139-143 
    Details
    ISSN: 1432-2072
    Keywords: Atropine ; Cholinergic mechanisms ; Learning ; Ontogeny ; Passive avoidance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The maturation of cholinergic inhibitory mechanisms that may be involved in passive-avoidance learning was studied in rats 14, 17, 21, 25, 28, and 34 days of age. Acquisition and extinction of the conditioned response were examined under saline and atropine sulfate (5 mg/kg). Learning was also tested following scopolamine hydrobromide injections (1, 4, 8 mg/kg) in rats 17 days of age and following α-methylatropine (5 mg/kg) in 17-and 34-day-old groups. In normal animals the rate of acquisition increased during ontogenesis, with a significant improvement between postnatal days 17 and 21, whereas the rate of extinction did not vary with age. Acquisition was impaired by atropine sulfate at all ages and even totally prevented in younger groups (14 and 17 days of age). It was also completely disrupted by scopolamine in 17-day-old rats. Extinction following acquisition under atropine was more rapid than after normal acquisition. Methyl-atropine was without effect. These results support the hypothesis of central cholinergic mechanisms involved in response suppression, already functioning in the rat 14 days of age and maturing mainly between the 17th and the 21st postnatal days.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00426769
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  • 36
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    The effects of psychotropic drugs on exploratory and stereotyped behaviour of rats studied on a hole-board (1977)
    Springer
    Psychopharmacology 55 (1977), S. 67-74 
    Details
    ISSN: 1432-2072
    Keywords: Rat ; Exploratory behaviour ; Stereotyped behaviour ; Hole-board ; dl-Amphetamine ; Haloperidol ; Apomorphine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Exploratory and stereotyped behaviour of Male Wistar rats was studied on a hole-board. The two forms of behaviour were differentiated according to the pattern of hole-dipping activity. Increasing doses of dl-amphetamine stimulated both forms of behaviour with stereotyped behaviour becoming predominant particularly at the higher dose levels. At the highest dose of amphetamine used (16 mg/kg) a gradual transition from exploratory to stereotyped behaviour was observed with time. As the drug wore off this transition was reversed. Haloperidol at a dosage of 0.1 and 0.05 mg/kg blocked the response to a high dose of amphetamine whereas a lower dose (0.02 mg/kg) blocked the stereotyped response to amphetamine while some exploratory behaviour still took place. Apomorphine inhibited hole-dipping but at lower doses another form of exploratory behaviour was induced, this behaviour becoming stereotyped as the dose was increased. It is concluded that there is a close relationship between exploratory and stereotyped behaviours. Monoamine systems appear to play a significant role in the regulation of both forms of behaviour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432819
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  • 37
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    Electronic Resource
    The effect of chronic ethanol treatment on behaviour and central monoamines in the rat (1977)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 300 (1977), S. 205-216 
    Details
    ISSN: 1432-1912
    Keywords: Chronic ethanol treatment ; Rat ; Behaviour ; Central monoamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats weaned at 16 days of age were treated with various ethanol concentrations (8–24% w/v) for 270 days. The effect of the chronic ethanol treatment on the growth rate, the diurnal pattern of drinking, the open field activity, and the conditioned avoidance acquisition and retention of the rats were studied. Termination of the chronic ethanol administration caused two types of withdrawal syndromes. The first, an acute withdrawal syndrome was observed within 12 h after the discontinuation of the ethanol treatment and was characterized by extreme hyperexcitability. The second, a delayed withdrawal syndrome was characterized by a more coordinated behavioural stimulation and developed first after about 3 days after the discontinuation of the ethanol treatment. Biochemically, the latter withdrawal syndrome was accompanied by an increased rate of tyrosine hydroxylation (measured as the accumulation of dopa after inhibition of aromatic amino acid decarboxylase) in the striatum and dopamine-rich limbic structures. No differences in the accumulation of 5-hydroxytryptophan were observed. Furthermore, there was an increased level of dopamine concomitant with a decreased level of noradrenaline in the limbic areas during ongoing ethanol treatment. On the 4th day after withdrawal of ethanol the endogenous levels of dopamine and noradrenaline were statistically significantly reduced in the limbic structures. The data of the present study indicate that chronic ethanol administration induces various kinds of behavioural changes and that these changes at least partially are mediated via central catecholamine mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500962
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  • 38
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    Electronic Resource
    Filaments and rod-shaped tubulated bodies in the endothelia of anterior cerebral arteries in young rats (1977)
    Springer
    Cell & tissue research 182 (1977), S. 505-511 
    Details
    ISSN: 1432-0878
    Keywords: Endothelium ; Cerebral artery ; Filaments ; Rod-shaped inclusion ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Endothelia of the anterior cerebral arteries in rats aged 1 to 3 days were studied. Thin (about 50–90 Å) and thick (about 100–110 Å) filaments are present in the endothelia. Numerous spherical- or rod-shaped bodies, measuring approximately 0.07 to 0.3 μm in diameter and up to 0.6 μm in length occur in the endothelial cells. These bodies contain a tubular structure. The diameter of the individual tubules is about 200 Å. The present observations suggest that spherical- or rod-shaped inclusions are first synthesized in the rough endoplasmic reticulum and thereafter these materials are transported into the Golgi complex for maturation. A small number of the inclusions, however, may originate directly from the rough endoplasmic reticulum and not pass through the Golgi apparatus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219832
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  • 39
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    Electronic Resource
    Transport adenosine triphosphatase activity in the rat cornea (1977)
    Springer
    Cell & tissue research 176 (1977), S. 431-443 
    Details
    ISSN: 1432-0878
    Keywords: Cornea ; Rat ; NaK-ATPase ; K-NPPase ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sodium-potassium activated adenosine triphosphatase (NaKATPase) activity of the rat cornea was investigated histochemically using a Pb2+-precipitation technique in which adenosine triphosphate (ATP) is used as substrate and two methods for potassium-dependent para-nitrophenyl-phosphatase (K-NPPase) activity. With all the three techniques used it was demonstrated that the sodium-potassium-activated adenosine triphosphatase (NaK-ATPase) activity is localized in the cell membranes of the endothelium whereas a much weaker activity was observed in the epithelium. When the Pb2+-technique was used, the epithelial cell membranes showed a weaker reaction in the presence of ouabain. This activity was only Mg2+-dependent and was presumably due to an Mg2+-dependent ATPase. The validity of the histochemical techniques for NaK-ATPase activity is discussed. The results emphasize the importance of the endothelium as the main site of Na+ transport in the cornea. Small amounts of the enzyme are also present in the epithelium, which seems to be rich in Mg2+-ATPase. Provided that careful controls are performed, all the methods give consistent results in the cornea.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231400
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  • 40
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    Electronic Resource
    Ultrastructure of the rat pineal gland grafted under the kidney capsule (1977)
    Springer
    Cell & tissue research 176 (1977), S. 131-142 
    Details
    ISSN: 1432-0878
    Keywords: Pineal gland ; Graft ; Ultrastructure ; Innervation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pineal glands were grafted under the kidney capsule of mature male rats for periods of 20, 40, 60 and 100 days. Each grafted gland was then excised and divided into two halves. One half was processed for conventional electron microscopy and the other was fixed in aldehydes and then incubated in a zinc iodide-osmium tetroxide mixture at pH 4.4 (A-ZIO-4.4). During the forty days following the operation pinealocytes showed the typical ultrastructural features associated with cells with a high protein and/or peptide secretory activity. On the other hand, during this period, the number of granular vesicles decreased progressively. From day 40 on, the grafted pinealocytes lacked granular vesicles. During the second half of the experimental period the ultrastructure of the pinealocytes indicated that their secretory activity was considerably decreased. During the acute phase of the experimental period numerous structures regarded as the tip of growing axons as well as typical nerve fibres appeared around blood vessels and within the parenchyma of the grafted gland. In the transplanted tissue obtained 60 and 100 days after the operation the growth cones were scarce, whereas typical nerve endings became numerous. These endings contained small clear vesicles which reacted positively when the tissue was treated with A-ZIO-4.4. The secretory activity of the grafted pineal gland and the nature of the nerve fibres which innervate the graft are discussed. The authors wish to thank Mrs. E.M. Rodríguez de Calderón for her valuable help
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220349
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  • 41
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    Electronic Resource
    Further evidence for the existence of intralobular nerves in the rat liver (1977)
    Springer
    Cell & tissue research 177 (1977), S. 287-290 
    Details
    ISSN: 1432-0878
    Keywords: Liver ; Intralobular nerves ; Rat ; Cobalt and Procion Yellow staining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In a recent study (Skaaring and Bierring, 1976) we found cholinesterase positive nerve-like structures in the lobules of rat liver, and scanning electron microscopy revealed cords having a distribution pattern similar to that of the cholinesterase-positive structures. To obtain further evidence for an intralobular nerve supply the methods of cobalt and Procion Yellow nerve staining (Stretton and Kravitz, 1968; Iles and Mulloney, 1971; Pitman, Tweedle and Cohen, 1972) were adapted, iontophoretic introduction of the dyes being attempted through cut axonal ends in the surface of small excised blocks of rat liver.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221089
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  • 42
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    Electronic Resource
    Regeneration of soleus muscles of rat autografted in toto as studied by electron microscopy (1977)
    Springer
    Cell & tissue research 177 (1977), S. 159-180 
    Details
    ISSN: 1432-0878
    Keywords: Muscle transplantation ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rat soleus muscles were autografted from right to left legs, and regeneration following necrosis of all original myofibres was studied after 7 to 250 days. The best regenerates were from grafts replacing all calf muscles and sutured to the tendon stumps. After 30 days the size of such regenerates was equal to those from minced gastrocnemius muscles: the cross sectional area of muscle tissue was 30% (1.7 mm2) and the number of fibres was 180% (4500) of normal soleus muscles; the fibre diameters were 10 to 40 μm. To increase the number of myoblasts before grafting some muscles were injured by Ringer solution of 70° C and transplanted after 2 days. Nevertheless, this did not influence regeneration. After 7 days clusters of myotubes occurred in the periphery of the muscle. These myotubes originated from myoblasts growing like endothelial cells on the inner face of the persisting basal lamina tubes of necrotic fibres. After 30 days the muscles were vascularized. Fibres formed in a common basal lamina detached and so looked “split”. Satellite cells of new fibres came from undifferentiated cells associated with myotubes, i.e. from myoblasts. After 30 days and more regenerates contained three sorts of fibres. 1. Thin (5 to 20 μm) fibres resembling fetal muscle fibres. They were most prominent after 30 days, and probably not yet innervated. 2. Thin (10 μm) degenerating fibres as in long-time denervated muscles. 3. Thick (more than 30 μm) mature looking fibres which were innervated and revealed end-plates. Half of the grafts studied after 30 and 60 days contained unmyelinated and myelinated axons which had grown along strands of surviving Schwann cells. After 250 days, only two muscles were studied which both lacked innervation. Almost all regenerates contained muscle spindles, which, however, were not innervated. Within the persisting spindle capsules new muscle fibres had been formed from satellite cells of the former intrafusal fibres.
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    URL: http://dx.doi.org/10.1007/BF00221079
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  • 43
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    Electronic Resource
    The development of innervation in the rat atrioventricular node (1977)
    Springer
    Cell & tissue research 178 (1977), S. 73-82 
    Details
    ISSN: 1432-0878
    Keywords: Atrioventricular node ; Rat ; Innervation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The problem of development of the innervation of the rat atrioventricular node has been investigated by electron microscopy. Nerve bundles appear in relation to the node as early as the second postnatal day and vesiculated axons are seen throughout the entire node by the fourth day. Intimate contacts between nodal cells, axons and terminal varicosities are frequently observed. Use of the 5-hydroxydopamine tracer technique has enabled the identification of both cholinergic and adrenergic axons. It is concluded that the node has a dual innervation although cholinergic endings far outnumber those classified as adrenergic on the sixth postnatal day. These results are quite different to earlier findings made at the light microscope level and the discrepancies are discussed with respect to the histochemical techniques used. The suggestion that nodal differentiation is induced by nerves is considered in relation to the differences in cholinesterase activity exhibited by nodal cells during normal development and following neonatal sympathectomy.
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    URL: http://dx.doi.org/10.1007/BF00232825
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  • 44
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    Electronic Resource
    Effects on gonadal function by lesioning tanycytes in the median eminence of the rat and Japanese quail (1977)
    Springer
    Cell & tissue research 178 (1977), S. 143-153 
    Details
    ISSN: 1432-0878
    Keywords: Median eminence ; Tanycytes ; Gonadal function ; Rat ; Japanese quail
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ependymal linings of the median eminence were destroyed by electric cautery or intraventricular injection of picric acid in the rat and Japanese quail. In these animals the ventricular lumen near the median eminence disappeared due to adhesion of lesioned walls on both sides of the third ventricle. Electric lesions of the ependymal layer containing tanycytes did not induce appreciable disturbance in the estrous cycles. Rats in which tanycytes were lesioned by picric acid displayed 4-day estrous cycles after prolonged diestrus (10–22 days). After destruction of tanycytes in the quail, a photostimulated gonadal growth was observed. It is concluded that the tanycyte transport of the ventricular fluid to capillaries of the portal vessels appears unnecessary for maintenance of adenohypophysial gonadotrophic activities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219042
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  • 45
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    Electronic Resource
    Effect of glucagon on the secretory process in the rat exocrine pancreas (1977)
    Springer
    Cell & tissue research 182 (1977), S. 193-204 
    Details
    ISSN: 1432-0878
    Keywords: Glucagon ; Exocrine pancreas ; Secretory process ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Glucagon was infused into conscious rats in doses of 10 to 80 μg/h for periods up to 24 h. The effect on the secretory process of the exocrine pancreas was studied in vitro using isolated pancreatic lobules. A pronounced inhibition of the rate of protein synthesis and discharge of stored and newly synthesized proteins combined with increased enzyme content in the pancreas were observed after 30 min infusion. This effect was absent after longer infusion periods of up to six hours. After 12 to 24 h infusions a marked degranulation and decrease in enzyme content was observed. While the rate of protein synthesis was not significantly enhanced, both the basal and stimulated discharge of enzymes from the pancreas were increased. The results suggest a biphasic response of the pancreas to prolonged glucagon infusion.
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    URL: http://dx.doi.org/10.1007/BF00220588
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  • 46
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    Electronic Resource
    Ultrastructural studies on the secretory cycle of the neurosecretory cells and the formation of herring bodies in the paraventricular nucleus of the rat (1977)
    Springer
    Cell & tissue research 177 (1977), S. 1-8 
    Details
    ISSN: 1432-0878
    Keywords: Paraventricular nucleus ; Rat ; Types of neurons ; Secretory cycle ; Herring body
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the neurosecretory cells in the paraventricular nucleus of the normal male rat was studied by electron microscopy during various functional states. Four morphologically distinct types of neurosecretory cells were observed. It appears that they do not represent different classes of cells but different phases of secretory activity of a single cell type. The perikarya of the neurosecretory cells show a definite cycle of formation and transportation of secretory granules. We have designated the phases of this cycle as: (1) phase of synthesis, (2) phase of granule production, (3) phase of granule storage and (4) phase of granule transport. The neurosecretory granules appear to be moved in bulk into the axons, forming a large axonal swelling filled with granules as a result of one cycle in the neurosecretory process. Thus it may be postulated that a secretory cycle in the perikaryon of the neurosecretory cell seems to result in the formation of a Herring body in its axon, and that its content is then conveyed to the posterior pituitary.
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    URL: http://dx.doi.org/10.1007/BF00221114
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  • 47
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    Der Einfluß des duodenogastrischen Refluxes auf das Epithel an der gastroenteralen Anastomose (1977)
    Springer
    Langenbeck's archives of surgery 344 (1977), S. 207-217 
    Details
    ISSN: 1435-2451
    Keywords: Gastroenterostomy ; Duodenal reflux ; Epithelial lesions ; Nitrosoguanidine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Einfluß des chronischen duodenogastrischen Refluxes auf die Magenschleimhaut des nicht resezierten Magens wurde im Hinblick auf die Disposition der gastroenteralen Anastomose für die Krebsentstehung tierexperimentell an männlichen Wistarratten untersucht. Hierzu wurden Tiere mit einer Gastroenterostomie ohne Enteroanastomose und Tiere, bei denen ein Reflux durch eine Y-Gastroenterostomie nach Roux ausgeschlossen war, mit einer zeitlich unterschwelligen Cancerogendosis (Nitrosoguanidin) exponiert. Es wird gezeigt, daß auch unabhängig von der Cancerogenexposition ein chronischer duodenogastrischer Reflux zu adenomartigen Drüsenproliferationen mit z. T. atypischen Epithelregeneraten an der Anastomose führt, die durch eine Gastroenterostomie nach Roux verhindert werden können. Anastomosencarcinome, wie in früheren Untersuchungen am resezierten Magen bei sonst gleichen Versuchsbedingungen beschrieben, konnten nicht induziert werden. Somit spielen für die Krebsentstehung an der gastroenteralen Anastomose neben dem Reflux auch die durch die Magenresektion selbst hervorgerufenen Veränderungen eine nicht unwesentlilche Rolle.
    Notes: Summary The cancerogenic effect of continous duodenal reflux on the gastric mucosa has been investigated in male Wistar-rats after gastrointestinal anastomosis. Groups of animals with gastroenterostomy without enteroenteral anastomosis and with Roux-en-y-anastomosis preventing duodenal reflux were treated with lower dosages of the cancerogenic Nitrosoguanidine. Proliferative mucosal alterations near the gastroenteral anastomosis were observed. In addition the gastric mucosa was characterized by adenomatous lesions caused by duodenal reflux. The changes detected were not influenced by Nitrosoguanidine and did not appear in cases of Roux-en-y-anastomosis.
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    URL: http://dx.doi.org/10.1007/BF01254075
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  • 48
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    Das Krebsrisiko im Resektionsmagen (1977)
    Springer
    Langenbeck's archives of surgery 344 (1977), S. 71-82 
    Details
    ISSN: 1435-2451
    Keywords: Cancer risk ; Resected stomach ; Rat ; Duodenogastric reflux ; N-methyl-N′-nitro-N-nitrosoguanidine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurde die Frage geprüft, ob obligater duodenogastrischer Reflux unter Langzeitbedingungen das Wachstum von Carcinomen oder Sarkomen im resezierten Magen beeinflußt. 72 männliche Wistarratten wurden einer Magenresektion unterworfen. Die erforderliche Gastroenteroanastomose wurde bei 39 Tieren als short loop GE (Billroth II) mit obligatem Reflux von Galle und Duodenalsekret in den Restmagen angelegt. Die restlichen 33 Tiere erhielten eine Y-förmige GE (nach Roux) mit seitlicher Einmündung des Duodenum in den Dünndarm; Reflux von Galle in den resezierten Magen war dadurch unmöglich. Die Carcinominduktion erfolgte durch kontinuierliche Gabe von N-Methyl-N'-Nitro-N-Nitrosoguanidin im Trinkwasser. Bei der Sektion der Tiere mit Reflux 33 Wochen nach Carcinogengabe fand sich die Mehrzahl der malignen Tumore von Magenstumpf, Anastomose (GE) und angrenzendem Dünndarm in der Tiergruppe mit obligatem Reflux (13 von 22). Die Tiergruppe ohne Reflux (Y-Roux GE) wies demgegenüber signifikant weniger Carcinome auf (7 von 21); die Tumorincidenz dieser Gruppe entsprach derjenigen eines nicht operierten Kontrollkollektives (5 von 22). - Die Ergebnisse unserer Untersuchungen zeigen, daß die in der Technik des short loop durchgeführte Gastroenteroanastomose des Billroth 11-Magens das Krebswachstum im Anastomosengebiet in besonders ausgeprägtem Maße fördert. Ausschlaggebend für die gesteigerte Carcinominduktion ist der chronische Reflux von Galle und Duodenalsekret, der bei der short loop-GE obligat über den Magnrest fließt.
    Notes: Summary The purpose of this study was to find whether the reflux of bile and pancreatic juices following stomach resection (duodenogastric reflux) enhances the incidence of carcinomas near the gastroenteric anastomosis. 72 male Wistar rats were subjected to stomach resection. The gastroenteric anastomosis (GE) was performed either as short loop anastomosis (Billroth II;n = 39), thus providing a continuous duodenogastric reflux, or as Y-shaped GE (according to Roux;n = 33). By the latter technique, bile and pancreatic juices are derived quantitatively into the jejunum without coming into contact with the remaining part of the stomach. During a period of 33 weeks, operated rats as well as intact animals were given the carcinogen N-methyl-N′-nitro-N-nitrosoguanidine (NG; 120 mg/1) in the drinking water. At autopsy, 33 to 36 weeks after daily oral administration of NG, most of the tumours were found in operated rats undergoing continuous ref lux (Billroth II group). In contrast to these findings, the incidence of carcinomas was significantly lower in animals without reflux (Roux group or intact control rats).-The results of our experiments demonstrate that, in rats, the duodenogastric reflux contributes substantially to the development of carcinomas of the resected stomach.
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    URL: http://dx.doi.org/10.1007/BF01259380
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  • 49
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    Bakterielle Besiedlung und Nitritbildung im Magen nach Gastroenterostomie (1977)
    Springer
    Langenbeck's archives of surgery 344 (1977), S. 109-114 
    Details
    ISSN: 1435-2451
    Keywords: Gastric carcinoma ; Gastroenterostomy ; Bacterial flora ; Nitrit ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Anlage einer Gastroenterostomie ohne Enteroanastomose führt zu einer Veränderung der bakteriellen Magenbesiedlung, wobei besonders der Anteil nitritspaltender Bakterien erhöht ist. Dies hat ein Ansteigen der Nitrit-Konzentration im Magensaft zur Folge. Die hierdurch mögliche vermehrte Bildung carcinogener Nitrosamine wird im Hinblick auf das Entstehen eines Carcinoms im operierten Magen diskutiert. Da die beschriebenen Veränderungen durch eine Gastroenterostomie nach Roux weitgehend verhindert werden, soll dies bei der Passagewiederherstellung nach Operation am Magen berücksichtigt werden.
    Notes: Summary A gastroenterostomy without enteroanastomosis leads to a change in the bacterial flora of the stomach, where-by in particular the proportion of nitrite-decomposing bacteria, is enhanced. This results in an increase of nitrite concentration in the gastric fluid, which may possibly be accompanied by an augmented production of carcinogenic nitrosoamine. This latter aspect is considered with respect to the origin of carcinoma in the operated stomach. Since the reported changes will be largely prevented by a Roux-Y-gastroenterostomy, this should be taken into consideration for reconstruction of the alimentary tract after gastric surgery.
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    Azimine. IITeil I, siehe [1].. Synthese und thermische Fragmentierung von cis- und trans-2,3-Diphenyl-1-phthalimido-2,3-di[15N]-aziminTeilweise vorgetragen in der Versammlung der Schweizerischen Chemischen Gesellschaft am 8./9. Oktober 1976 in Genf und als Autoreferat veröffentlicht [2]. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 831-843 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Azimines. IITeil I, siehe [1]. . Preparation and Thermal Fragmentation of cis- and trans-2,3-Diphenyl-1-phthalimido-2,3-di[15N]-azimine Teilweise vorgetragen in der Versammlung der Schweizerischen Chemischen Gesellschaft am 8./9. Oktober 1976 in Genf und als Autoreferat veröffentlicht [2].cis- and trans-2,3-Diphenyl-1-phthalimido-2,3-di[15N]-azimine (11 and 12) wer synthesized from cis-di[15N]-azobenzene (10) and phthalimido-nitrene (2), the latter generated by lead tetraacetate oxidation of N-aminophthalimide (1). Useful information was obtained from the comparison of several data of 11 and 12 with those of the unmarked diphenyl-azimines 5 and 6 (R = C6H5).The 15N- and 13C-NMR. spectra of 11 and 12 were interpreted to furnish additional evidence for the azimine structure and for the indicated configurations. The IR. spectra permitted identification of two bands in the 1200 to 1450 cm-1 region, probably characteristic for the functionality of diaryl-phthalimido-azimines. Comparison of the mass spectrum of 11/12 with that of the unmarked analogues 5/6 (R = C6H5) permitted the interpretation of the fragmentation path of 1-phthalimidoazimines. The major path may be the purely thermal decomposition to 13 and 7 (R = C6H5), respectively. Two other competing fragmentation paths are discussed.Prolonged thermolysis of 11 at 61° in solution gave 83% of N,N′-diphenyl-N N′-phthaloyl-di[15N]-hydrazine (13) of 98% isotope purity, which means that the imide nitrogen atom and N(1) of the azimine function are removed in this reaction. A mechanism passing through an intermediate cyclic tetrazene 16 is considered.Benzocyclobutenedione (14) added to trans-azobenzene (4, R = C6H5) under the influence of a high pressure lamp in a quarz apparatus to give N,N′-diphenyl-N,N′-phthaloyl-hydrazine (7, R = C6H5). This reaction was found not to take place in the dark, even after prolonged heating in trichloromethane.
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    Azimine. I. Bildung und Stereoisomerie von 2, 3-Diaryl- und 2, 3-Dialkyl-1-phthalimido-aziminenTeilweise vorgetragen in der Versammlung der Schweizerischen Chemischen Gesellschaft in Lausanne am 7./8. Mai 1971 und als Autoreferat veröffentlicht [1]. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 816-830 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Azimines. I. Synthesis and Stereoisomerism of 2, 3-Diaryl- and 2, 3-Dialkyl-1-phthalimido-aziminesTeilweise vorgetragen in der Versammlung der Schweizerischen Chemischen Gesellschaft in Lausanne am 7./8. Mai 1971 und als Autoreferat veröffentlicht [1].Special examples of a new class of compounds, the open-chain azimines (1), have been prepared and their properties examined.Addition of phthalimido-nitrene (4), generated by lead tetraacetate oxidation of N-aminophthalimide (3), to cis- and trans-azobenzene (6 and 5), -azo-p-toluene (8 and 7), and to trans-azomethane (9), -azoethane (10) and -azo-α-phenylethane (11) afforded the separable cis- and trans-isomers of 2, 3-diphenyl- (12 and 13), 2, 3-di-p-toyl- (14 and 15), 2, 3-dimethyl- (16 and 17), 2, 3-diethyl- (18 and 19) and 2, 3-di-(α-phenylethyl)-1-phthalimido-azimines (20 and 21) in different ratios (see Scheme 1).The constitution of the nitrene azo compound adducts as azimines was derived from their properties, especially from the conjugation effect (visible in the UV. spectra) of the aryl-substituted compounds and from the non-equivalence (shown by the 1H-NMR. spectra) of the substituents on the two nitrogen atoms derived from the azo compounds. This evidence excluded the triaziridine 22 and an alternative azimine constitution 23 for the adducts.Of the two stereoisomers obtained for each of the azimines, the aryl-substituted examples 12/13 and 14/15 were readily interconverted by warming in solution, the cis-isomers 12 and 14 exceeding the trans-isomers 13 and 15 in the equilibrium. The dialkyl-azimines appear to be configurationally more stable, since interconversion of the dimethyl-azimines 16 and 17 was not possible under the same conditions, and also not before another thermal reaction took place (see below).The identification of the N(2)-N(3) bond as the stereogenic center, i.e. that the stereoisomerism of the azimines is due to the difference in relative position at N(2) and N(3) of the substituents derived from the azo compounds, as well as a configurational assignment was possible in the aryl-substituted examples on the basis of the UV. spectroscopic comparison of the isomeric azimines with the corresponding stereoisomeric azoxy compounds: The cis-azimines 12 and 14 showed absorptions similar to those of cis-azoxybenzene and cis-azoxy-p-toluene, and the trans-azimines 13 and 15 showed absorptions similar to those of the respective trans-azoxy compounds. With respect to the configuration of the alkyl-substituted azimines, it was observed that the isomers 17 and 19, which from their formation and chromatographic behaviour are likely to be the trans-isomers, show a visible coupling (∽ 1 Hz) between the two H (α)'s in the 1H-NMR. spectrum, whereas the dimethyl isomer 16 (cis) does not exhibit such a coupling.Thermal treatment of four azimines, namely 12, 14, 16 and 17, in solution for a longer time afforded the corresponding N, N′-disubstituted N, N′-phthaloyl-hydrazines 27, 28 and 29. The order of velocity of this fragmentation with nitrogen extrusion was 12/13 ≍ 14/15 〉 16(cis) 〉 17(trans).
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    Photochemistry of Chlorinated 2-Cycloalkenones (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 874-881 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 6-chloro-2-cyclohexenones 3, 6 and 11, and the 5-chloro-2-cyclopentenone 15 were newly synthesized. The results obtained with compounds 3 and 15 in photocycloadditions to olefins show that the oxetane vs. cyclobutane product ratio is reduced by the substitution of florine by chlorine in the α′ -position of the enone. No oxetanes are formed in the intramolecular photocycloaddition of 6. Compound 11 does not photoadd to olefins. The newly synthesized 2-chloro-3-cyclohexenones 8 and 9 are also photostable towards light of λ=366 nm, but π-π*-excitation (λ=254 nm) in pentane leads to the formation of 4,4-dimethylcyclohexanone (29).
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    Mehrkernige Kobaltkomplexe. II. Herstellung und Struktur von [(tren) (NH3)Co(O2)Co(NH3) (tren)](SCN)4 · 2H2OI: siehe [1]. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 867-873 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polynuclear Cobalt Complexes. II. Preparation and Structure of [(tren) (NH3)Co(O2)Co(NH3) (tren)](SCN)4 · 2H2OThe title compound is obtained on oxygenation of [Co(tren)(H2O)2]2+ in 6M aqueous ammonia or by ligand exchange starting from [(NH3)5Co(O2)Co(NH3)5]-(NO3)4. An X-ray structure determination was made. The substance forms monoclinic crystals, space group P21/c, lattice constants a=10,135, b=8,473, c=19,484 Å, β=108,58°, with two formula units in the cell. The final R is 0,066. The binuclear cation has a center of symmetry, so the Co—O—O—Co unit is planar; the Co—O—O angle is 111,5°. The tertiary nitrogen atoms of both chelate groups are cis to the O2 bridge, as found in doubly bridged [(tren)Co(O2,OH)Co(tren)](ClO4)3 · 3H2O.On acidification in solution, the singly bridged cation [(tren) (NH3)CoO2Co(NH3)(tren)]4+ (a) loses the bound O2 completely. But unlike the doubly bridged cation b, the rate of dissociation of a is independent of pH (Fig. 5). At higher pH (8-10) bridging a→b (Fig. 2) occurs. Both reactions must have the same rate determining step, the first order rate constants being of the order of 2 · 10-3 s-1 (25°, 0,35M KCl).
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    Isolation and Identification of Three Major Metabolites of Retinoic Acid from Rat Feces (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 881-887 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Following the intraperitoneal administration of high doses of 14C- and 3H- labelled retinoic acid (1) to rats, three major metabolites and the intact compound were isolated from the feces in microgram amounts by use of column, thin-layer and high-pressure liquid chromatography. Their structures were elucidated by mass spectrometry and Fourier Transform 1H-NMR. spectroscopy as 2 (all-trans-4-oxoretinoic acid), 3 (7-trans-9-cis-11-trans-13-trans-5′-hydroxy-retinoic acid).Hydroxylation of the 5-methyl group of the cyclohexene ring, oxidation of the cyclohexene ring in position 4 and cis-trans isomerisation of the nonatetraenoic acid side chain were the reactions, which produced these products from retinoic acid. The metabolites 2 and 4 each accounted for about 4% of the radioactivity administered. The metabolite 3 and the parent compound accounted for about 16% and 17% of the dose, respectively.
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    Nouveaux types de sucres acétyléniques. Communication préliminaireUne communication plus détaillée paraîtra ultérieurement. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 892-895 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel types of acetylenic sugarsThe coupling, following Cadiot's procedure, of a 6-bromo-5,6-dideoxy-1,2-O-isopropylidène-3-O-methyl-α-D-xylo-hex-5-yno-1, 4-furanose (1) with phenylacetylene, 2-propyn-1-ol or terminal acetylenic sugars gave with excellent yields the expected diynes (an enediyne when the terminal acetylene was the 3,5, 6-trideoxy-1,2-O-isopropylidene-α-D-glycero-hex-3-en-5-yno-1,4-furanose 7). The chloro analogue 8 of 1 on treatment with lithium thiophenate gave the corresponding phenylthio-acetylenic sugar 9. An acetylene was also formed by reacting the gem-difluoro-olefinic sugar 10 with butyllithium whereas the same olefinic sugar and its 3-O-benzyl analogue 11 gave only a gem-fluoro-arylthio-olefinic sugar (13-15) as a mixture of the Z and E isomers (Z/E 〉 4) when treated with the conjugate base of an arylmercaptan.
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    Nouveaux exemples de radicaux libres stables de dérivés hétérocycliques de sucresDérivés C-glycosyliques XXXIV. Pour la 33c communication v. [1].. Communication préliminaireUne communication plus détaillée paraîtra ultérieurement. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 888-891 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some more examples of stable free radicals of carbohydrate heterocyclic derivatives2-Glycosyl-4,4,5,5-tetramethylimidazoline- 3-oxide-1-oxyls and 2-glycosyl-4,4,5,5-tetramethylimidazoline 1-oxyls have been prepared in nine carbohydrate series, which proves the generality of the method. The hyperfine coupling constant between the free electron and the α-proton of the glycosyl group is never very large (0-2.3 G) but a correlation between its value and the structure of the aglycone has been noted. Free radicals of that type, stable in aqueous solutions, are potentially interesting for biological studies.
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    The Structure of the Antibiotic Hedamycin. I. Chemical, Physical and Spectral PropertiesPresented in part at the fall meeting on the Swiss Chemical Society in Aarau, October 4, 1975. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 896-906 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Interpretation of the chemical and spectral (IR., UV., 1H- and 13C-NMR.) properties of the antitumor antibiotic hedamycin (C41H50N2O11) suggests that the molecule contains a methyl substituted 1-hydroxyanthraquinone nucleus, an α, β-unsaturated ketone, two sugar-like tetrahydropyran rings (4 and 8) and an aliphatic chain 2, presumably with an epoxy group (see the Scheme).
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    Halogenierte Pyridine und 1,8-Naphthyridine. VI (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 907-921 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Halogenated pyridines and 1,8-naphthyridines. VI.The principle of the synthesis of 3-halomethyl-2,6-dichloro-pyridines has been extended to compounds with side chains of more than one carbon atom in the 3-position. Feasible synthetic routes are outlined starting from cheap, commercially available α-methylideneglutaronitrile and trichloroalkyl functional compounds which yield the intermediate 1,3,5-trisubstituted alkanes. These are cyclized by aqueous mineral acid or by hydrogen bromide in an organic solvent to 2-substituted glutarimids or hexahydronaphthyridinones, depending on the mode of cyclization. The final aromatization provides a simple route to pyridines or 1, 8-naphthyridines.
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    Über Pterinchemie. 62. Mitteilung. Protonenkatalysierte [1,2]-H-Verschiebung bei der Umlagerung von 6,7-Diphenyl-5,6-dihydropterin zu 6,7-Diphenyl-7,8-dihydropterin (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 922-924 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Proton catalysed [1,2]-H-shift in the rearrangement of 6,7-diphenyl-5,6-dihydropterine (I) to 6,7-diphenyl-7,8-dihydropterine (III)The arrangement from I to the thermodynamically more stable III undergoes through a acid catalysed [1,2]-H-shift (intramolecular 6,7-hydride rearrangement) (see Scheme 1).
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    Reactions of 1,3,5,7-Tetramethyl-anti-tricyclo[5.1.0.03,5] octane-2,6-diols and their 4,4,8,8-Tetrachloro- and 4,8-Dichloro-Derivatives with Diphosphorus TetraiodideFrom the planned dissertation of R. A. Dyllick-Brenzinger, ETH Zürich. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1403-1415 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaktionen von 1,3,5,7-Tetramethyl-anti-tricyclo[5.1.0.03,5]octan-2,6-diolen und deren 4,4,8,8-Tetrachlor- und 4,8-Dichlorderivaten mit DiphosphortetrajodidEs wurden die P2I4-Reaktionen mit 1,3,5,7-Tetramethyl-anti-tricyclo[5.1.0.03,5]-octan-2,6-diolen (3/6), mit dem 4,8-Dichlorderivat 4 und mit den 4,4,8,8-Tetrachlorderivaten 5/7 untersucht. Dabei entstanden die Styrolderivate 9 und 12, die anti-Bishomobenzolderivate 8 und 11, ein Homotropylidenderivat 10, ein Cyclo-octatetraenderivat 13 und ein 9-Oxabicyclo[4.2.1]nona-2,4,7-trienderivat 15. Die Ausbeuten lagen zwischen 1 und 10%. Die Bildung aller dieser Produkte liess sich unter der Annahme der primären Umwandlung einer oder beider Hydroxylgruppen in Abgangsgruppen X oder X und Y (wahrscheinlich X=Y=I) mechanistisch deuten. Die Reaktion der Deschlorderivate 3/6 lieferte nach Substitution beider Hydroxyl-gruppen durch X und Y: (a) unter Abspaltung von HX und HY das Styrolderivat 9 (Schema 2) und (b) unter Abspaltung von XY das Homotropylidenderivat 10 (Schema 3a) und das Bishomobenzolderivat 8 (Schema 3b). Die Reaktion des 4,8-Dichlor-derivates 4 lieferte nach Substitution beider Hydroxylgruppen durch X und Y: (a) unter Abspaltung von HX und HY das Styrolderivat 12 (Schema 2), und (b) unter Abspaltung von XY das Bishomobenzolderivat 11 (Schema 3b). Die Reaktion mit den 4,4,8,8-Tetrachlorderivaten 5/7 lieferte: (a) nach Substitution beider Hydroxyl-gruppen durch X und Y unter Abspaltung von XCl und YCl das Cyclooctatetraen-derivat 13 (Schema 4), und (b) nach Substitution nur einer Hydroxylgruppe durch X unter Abspaltung von XCl und HCl das bicyclische Derivat 15 (Schema 5). Alle diese Reaktionen sind zusätzlich zu den angegebenen Fragmentierungen und Eliminierungen noch teilweise von Umlagerungen des Kohlenstoffgerüstes begleitet.Die thermische Umlagerung von 1,5-Dichlor-2,4,6,8-tetramethyl-cycloocta-1,3,5,7-tetraen (13) in das Styrolderivat 12 wurde in Abhängigkeit der Lösungs-mittelpolarität untersucht und mit der analogen thermischen Umlagerung von Brom-cyclooctatetraen und Chlor-cyclooctatetraen verglichen.
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    Diterpenoide Drüsenfarbstoffe: Coleone S und T aus Plectranthus caninus ROTH(Labiatae), ein neues Diosphenol/trans-A/B-6,7-Diketon-Paar aus der Abietanreihe (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1443-1447 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Leaf-gland Pigments: Coleons S and T from Plectranthus caninus ROTH (Labiatae), New Hydroquinones of the Abietane Series with a Diosphenol/trans-A/B-6,7-Diketone Structure.Coleons S and T were isolated from the more polar fractions from extracts of the above mentioned plant. Coleon S, C20H26O6, has been shown to have structure 1a, and coleon T, C20H26O6, structure 2.
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    Über eine Synthese des angulären Di(cyclobuteno)benzols (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1452-1455 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On a Synthesis of the angular Di(cyclobuteno)benzolIn the course of our studies aimed at better understanding the Mills-Nixon effect, we have also prepared the angular di(cyclobuteno)benzene (1), the synthesis of which has been recently described by another group [3]. Our completely different and essentially simpler synthetic approach will be pointed out. A special pyrolysis apparatus is designed.
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    Erratum (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1455-1455 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1002/hlca.19770600439
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    Mitteilungen (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1456-1458 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    URL: http://dx.doi.org/10.1002/hlca.19770600440
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    Masthead (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977) 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600501
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    Iron Carbonyl Induced Reactions of Norbornene Derivatives with Substituted Acetylenes (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2160-2170 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemical reactions of norbornadiene with substituted acetylenes in the presence of Fe(CO)5 gave various products of different types, depending on the nature of the acetylene. The results are summarized in Table 1. The cyclopentanone 1 was always formed in these reactions. In the reaction of disubstituted acetylenes such as dimethyl acetylenedicarboxylate and ethyl phenylpropiolate, the cyclopentenones 2 and 5 were formed, respectively. By contrast, propiolic esters produced the cyclohexenones 3 and 4, in which the ester group was attached on the β carbon with respect to the keto group. Plausible mechanisms for the formation of these products are shown in Schemes 7 and 8. The reaction of diphenylacetylene gave the cyclohexendione 7 as well as the cyclopentenone 6. Two enedione products 8 and 9 were obtained from the reaction of phenylacetylene. Compound 9 was converted to the aromatic diacetate 13 by heating with acetic anhydride in pyridine. On irradiation in the presence of Fe(CO)5 norbornene reacted similarly with dimethyl acetylenedicarboxylate and phenylacetylene to give the cyclopentenone 14 and the cyclohexenone 15, respectively. Compound 15, upon heating, isomerized to hydroquinone 16, which on acetylation gave the diacetate 17.
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    Application of the Equivalent Bond Orbital Model to the C2s-Ionization Energies of Saturated Hydrocarbons (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2234-2247 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that the ab initio STO-3G treatment applied to simple saturated linear, branched and cyclic hydrocarbons, assuming standard geometries, yields orbital energies ∊jSTO-3G for their canonical orbital ϕj which correlate perfectly with the observed C2s ionization energies Ijm, if Koopmans' approximation is accepted.Applying the Foster-Boys localization procedure to these canonical orbitals ϕj leads to localized orbitals λμ and their corresponding Hartree-Fock matrix Fλ = (Fλ,μv). An examination of the matrix elements Fλ,μv, i.e. of the self-energies Aμ = Fλ,μμ of the localized CC- and CH-orbitals λμ and of the cross terms Fλ, μv (μ ≠ v) between them, leads to the conclusion that a satisfactory approximation should be obtained by setting Aμ = A for all μ, Fλ,μv = B if λμ and λv are vicinal and neglecting all other cross terms. The resulting model is nothing but the well-known equivalent bond orbital model of Lennard-Jones & Hall, which however can now be calibrated using the known C2s-ionization energies of hydrocarbons. Due to the discrete structure and the wider range (∽ 8 eV) of the C2s band systems in the photoelectron spectra of these molecules this leads to a more satisfactory parametrization than using the narrower and badly resolved C2p band system.Comparison of calculated band positions using the calibrated model with observed C2s-band ionization energies for a series of hydrocarbons reveals that the simple equivalent bond orbital model is better than one might have expected.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19770600715
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    Der Metabolismus des Retinoids Ro 10-9359. Isolierung und Identifizierung der Hauptmetaboliten aus Plasma, Urin und Faeces des Menschen sowie aus der Galle der Ratte Synthese von drei Urinmetaboliten (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2309-2325 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Metabolism of the Retinoid Ro 10-9359. Isolation and Identification of the Major Metabolites in Human Plasma, Urine and Feces Synthesis of Three Urinary MetabolitesAfter oral administration of therapeutic doses of the 3H-labelled aromatic retinoic acid analog (retinoid) Ro 10-9359 (ethyl all-trans-9-(4-methoxy-2,3,6-trimethyl-phenyl)-3,7-dimethyl-2,4,6,8-nonatetraenoate) to humans 75 and 15% of the 3H-dose were excreted within the first five days in the feces and the urine, respectively. Using chromatographic procedures including high pressure liquid chromatography 18 metabolites could be isolated from human urine. Their structures were elucidated by mass spectrometry and FT-1H-NMR. spectroscopy. In these urinary metabolites the tetraene side chain of the parent compound Ro 10-9359 is shortened. The radioactivity of the identified urinary metabolites accounted for about 11% of the dose. Three urinary metabolites were synthesized. The main part of the radioactivity excreted within the first five days in the feces consisted of unchanged drug (60% of the dose). A smaller (amount 15% of the dose) could not be identified. The unchanged drug and a major metabolite, the corresponding acid, were found in human plasma.In an experiment with bile-duct cannulated rats the radioactively labelled retinoid Ro 10-9359 was injected intravenously. About 70% of the 3H-dose was excreted in the bile, within the first 48 hours. The whole radioactivity of the rat bile consisted of polar metabolites. No unchanged drug could be found. After enzymatic hydrolysis of the bile conjugates three metabolites were isolated. The main metabolite (49% of the i.v. dose) was a conjugate of the corresponding acid of the parent drug, already found as free compound in human plasma. The other bile metabolites (9 and 7% of the i.v. dose) had an intact side chain, too.An enterohepatic recycling of the bile metabolites was observed in the rat.
    Additional Material: 4 Tab.
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    Stabilité en solution aqueuse de complexes de métaux lourds avec des ligands diaza-polyoxamacrocycliques (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2633-2643 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Stability in aqueous solution of some complexes of heavy metals with diaza-polyoxamacrocyclic ligandsStability of metal complexes (Mn+ = Cu2+, Ni2+, Co2+, Zn2+, Pb2+, Ag+ and Cd2+) with five diaza-polyoxamacrocycles (L = [2.1.1], [2.2.1], [2.2.2], [2.1] and [2.2] ) have been determined at 25°, in 0.1 M Et4N+ClO4- aqueous solutions, by means of potentiometric titrations. All cations form MLn+ complexes; Cu2+ also forms the MHL(n+1)+ protonated species with both [2.2.1] and [2.1.1] ligands. The stability of these complexes has been discussed in terms of structure and by considering the ionic radii of the cations together with the radii of the macrocyclic cavities. Different behaviour is observed between some of these complexes and the well known alkali and alkaline-earth cryptates, partly due to the more covalent nature of bonds formed by the investigated cations and the donor sites of the ligands. The effect of the substitution of two oxygen by two sulfur atoms in the pentadentate ligand [2.1] on the stability of the complexes is reported.
    Additional Material: 1 Ill.
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    Electron Transfer in Monolayer Assemblies with Incorporated Ruthenium (II) ComplexesHerrn Dr. Guido Schetty zum 65. Geburtstag freundlich zugeeignet (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2608-2632 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An arrangement for light induced vectorial charge separation is discussed in which the electron of the excited dye is transferred to an acceptor and the dye is recovered by electron tunneling through a high and narrow potential barrier. The possible relevance of the model in connection with photosynthesis is considered. Monolayers of Ru(II)-bipyridine complexes with long chain hydrocarbon substituents were investigated which may be useful as component in such arrangements.The surface pressure area isotherms of the monolayers were measured for various ionic compositions of the subphase, and the results demonstrate a strong effect of these ions on the structure of the layers. The layers were deposited on different substrates. The luminescence and its change by contacting the sample with water and by subsequent drying were found to be strongly dependent on the architecture of the layer assembly. Attempts of a photochemical cleavage of water with these assemblies failed.The pH-dependence of the absorption and the luminescence of a Ru(II) bipyridine-dicarboxylic acid complex in solution is interpreted by assuming that the electron in the excited state is localized in one pyridine part of the substituted ligand, the conjugation with the second half of the bipyridine carboxylic acid being negligible. Monolayer assemblies for measuring the energy transfer from the ruthenium complex to an adequate energy acceptor and from an adequate energy donor to the ruthenium complex were investigated. The results demonstrate that the deactivation of the excited ruthenium complex occurs mainly by passing the luminescent state.Assemblies were investigated for measuring the electron transfer from the excited ruthenium complex to an appropriate electron acceptor positioned in the carboxylate portion at the same interface as the electron donor. With bipyridinium ions as acceptor the ruthenium complex luminescence is quenched at average distances between acceptor molecules of about 10 Å, while this distance is 30, 60 und 75 Å for different cyanine dyes used instead of the ruthenium complex. A correlation between this distance and the ionization energy in the excited state of the donor is observed.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19770600814
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    Synthese von Nickelkomplexen mit porphinoidem Ligandsystem2. Mitt. über Synthese und Reaktionen von Metallkomplexen mit porphinoidem Ligandsystem. 1. Mitt. siehe [1].Herrn Dr. Guido Schetty zu seinem 65. Geburtstag gewidmet (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2644-2652 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of nickel complexes with a porphine-type ligand systemIn the presence of nickel(II) salts the bicyclic vinylogous amidine 1 is dimerized to the diamagnetic (1-amino-10,20-diaza-octahydroporphinato)nickel(II) complex 3. The condensation proceeds through a paramagnetic octahedral nickel(II) complex 2. Starting from 3, the (hexadecamethyl-10,20-diaza-hexahydroporphin)nickel bis (tetrafluoroborate) 7 (a (hexaaza [16]annulene)nickel(II) complex) was prepared in two steps. This highly electrophilic compound adds methoxide ions in consecutive and reversible steps to form first the (1-methoxy-10,20-diaza-octahydroporphinato)nickel tetrafluoroborate 8 and then the [cis-1, 11-dimethoxy-decahydroporphinato (2-)]nickel 6. 6, 7 and 8 were fully characterized and interconverted by addition and elimination reactions.
    Additional Material: 1 Tab.
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    The Reaction of Biadamantylidene with Singlet Oxygen in the Presence of Dyes [1] (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2673-2685 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Singlet oxygen, generated chemically or photogenetically, reacts with biadamantylidene to give the corresponding dioxetane and epoxide only. When methylene blue (MB) or meso-tetraphenylporphin (m-TPP) is used as sensitizer the normal reaction course occurs giving dioxetane as the preponderant product in 2-propanol, ethyl acetate, acetone, pinacolone, methylene chloride, chloroform, carbon tetrachloride and benzene, although in the last two solvents some 10-25% of epoxide is formed. When erythrosin and rose bengal (RB) are used, epoxide becomes the main product (70-95%). Epoxide does not derive from chemical reaction with the solvent. Pinacolone, for example, is not oxidized to t-butyl acetate.The rose bengal reaction involves both singlet oxygen and radicals, since diazabicyclooctane (DABCO) and di-t-butyl-p-cresol interfere with the oxidation. A mechanistic scheme is proposed in which sensitizer and oxygen combine to produce sensitizer radical cation and superoxide radical anion. Subsequently, hydroperoxy radical, deriving from superoxide, reacts with substrate to give epoxide and hydroxy radicals. The latter adds to substrate to give a new radical which captures triplet oxygen. Epoxide is formed by loss of hydroperoxy radical and the chain starts anew. The dioxetane is formed separately either by [2+2]-cycloaddition or stepwise addition.
    Additional Material: 8 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19770600818
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    Photochemische und nicht-photochemische A/D-Secocorrin→Corrin-Cyclisierungen bei 19-Carboxy- und 19-Formyl-1-methyliden-1,19-secocorrinaten. Decarboxylierbarkeit und Deformylierbarkeit von Nickel (II)-19-carboxy- bzw. 19-formyl-corrinaten. Vorläufige MitteilungLetzterschienene Mitteilungen über Corrinoide siehe [1-3] und die Zusammenfassung dieser Arbeiten in [4]. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2653-2672 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemical and non-photochemical A/D-secocorrin→corrin-cyclizations of 19-carboxy- and 19-formyl-1-methylidene-1,19-secocorrinates. Decarboxylation (and deformylation) of nickel(II)-19-carboxy-(resp. 19-formyl)-corrinatesNickel (II) 1-methylidene-2,2,7,7,12,12-hexamethyl-15-cyano-19-carboxy-1,19-secocorrinate can be induced to cyclize with concomitant decarboxylation to the corresponding corrinate (Scheme 9). Experiments with deuterated derivatives (Scheme 10) indicate that in this decarboxylative A/D-secocorrin→corrin-cyclization the ring closure step precedes decarboxylation. In accord therewith is the finding that the corresponding intermediate nickel(II) 19-carboxy-corrinate (synthesized via photochemical cyclization of the corresponding cadmium complex, Schemes 6 and 9) decarboxylates under very mild conditions.Nickel(II) 1-methylidene-2,2,7,7,12,12-hexamethyl-15-cyano-19-formyl-1,19-secocorrinate cyclizes smoothly to the corresponding 19-formyl-corrinate in the presence of acetic acid/triethylamine. The formyl group of the cyclization product can be eliminated hydrolytically in essentially quantitative yield by treatment with 2N KOH in ethanolic solution (Scheme 11). The non-photochemical (A→D)-cyclization of 19-formyl-1,19-secocorrinoids represents formation of the corrin chromophore at the oxidation level of porphyrinogens and exemplifies how a C1-fragment that eventually leaves the ligand can fulfill a specific function in the (A→D)-ring closure to a corrin.
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    URL: http://dx.doi.org/10.1002/hlca.19770600817
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    Diterpenoide Drüsenfarbstoffe aus Labiaten: 3β-Acetoxyfuerstion, Nilgherron A und Nilgherron B, neue Chinomethane aus Plectranthus nilgherricus BENTH.; absolute Konfiguration von Fuerstion (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2789-2803 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Leaf-gland Pigments: 3β-Acetoxyfuerstione, Nilgherron A and Nilgherron B, New Quinomethanes from Plectranthus nilgherricus BENTH. (Labiatae); Absolute Configuration of FuerstioneWe have isolated from leaf-glands of the above mentioned plant the following deeply coloured quino-methane derivatives: (1) traces of the already known fuerstione (1a); 11,15-dihydroxy-5,7,9 (11), 13-abietatetraen-12-one; (2) the new 3β-acetoxy-fuerstione (1b); (3) nilgherron A (5a, I or II), a new dimeric diterpenoid quinomethane, C40H52O7, formed in the plant obviously by cycloaddition of the o-quinone 8 (9aS, 11R)-11 -hydroxy-2-(1-hydroxy-1-methylethyl-9,9-dimethyl-3,4,7,8,9,9a,10,11- octahydro-5H-dibenzo [a, d]cycloheptene-3,4-dione) with fuerstione; (4) nilgherron B (5b, I or II), C42H54O9, likewise a new compound, formed by the same type of cycloaddition (heterodiene synthesis) of 8 with 3β-acetoxyfuerstione. On the basis of 1H-NMR. shift arguments structure I is slightly preferred to II for 5a and 5b. Model experiments have shown the easy formation of the dihydrodioxin ring by reaction of an o-benzoquinone with p-quinomethanes. The absolute configuration of fuerstione and 3β-acetoxyfuerstione has been determined by chiroptical methods.
    Additional Material: 1 Ill.
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    Transition metal complexes with bidentate ligands spanning trans-positions. IVPart III: see [1].. Preparation and properties of some rhodium and iridium complexes of 2,11-bis(diphenylphosphinomethyl)benzo [c]phenanthrene (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2804-2814 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The bidentate phosphine 2,11-bis(diphenylphosphinomethyl)benzo [c]phenanthrene (1) has been used to prepare the mononuclear, square planar complexes trans-[MX(CO)(1)] and trans-[M(CO)(CH3CN)(1)][BF4] (M = Rh, Ir; X = Cl, Br, I, NCS). It is found that the tendency of these complexes to form adducts with CO, O2 and SO2 is significantly lower than that of the corresponding Ph3P complexes. The oxidative-addition reactions of complexes trans-[IrX (CO) (1)] with hydrogen halides give the six-coordinate species [IrHX2(CO) (1)]. The complexes [IrH2I (CO) (1)] and [IrH2L (CO) (1)] [BF4] (L = CO and CH3CN) have been obtained from hydrogen and the corresponding substrates. The model compounds trans-[MCl (CO) (Ph2PCH2Ph)2] (M = Rh, Ir), trans-[Ir (CO) (CH3CN) (Ph2PCH2Ph)2] [BF4], [IrHCl2(CO)(Ph2PCH2Ph)2] and [IrH2(CO)2(Ph2PCH2Ph)2] [BF4] have been prepared and their special parameters are compared with those of the corresponding complexes of ligand 1. The influence of the static requirements of this ligand on the chemistry of its rhodium and iridium complexes is discussed.
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    Transition metal complexes with bidentate ligands spanning trans-positions. VIPart V: See [1].. The preparation of some diaryl- and dialkyl derivatives of 2,11-bis (phosphinomethyl)benzo [c]phenanthrene (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 2824-2829 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of the ditertiary phosphines 2,11-bis (di-m-tolylphosphinomethyl)benzo [c]phenanthrene (1b), 2,11-bis (di-p-anisylphosphinomethyl)benzo-[c]phenanthrene (1c), 2,11-bis (di-m-trifluoromethylphenylphosphinomethyl) benzo-[c]phenanthrene (1d), 2,11-bis (dicyclohexylphosphinomethyl)benzo [c]phenanthrene (1e) and 2,11-bis [di-(t-butyl)phosphinomethyl]benzo [c]phenanthrene (1f), by a combination of synthetic routes is described.
    Additional Material: 2 Tab.
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    Isolierung von (-)-Dunnion aus Calceolaria integrifolia MURR. (Scrophulariaceae) (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 945-947 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Isolation of (-)-dunnione from the leaves of Calceolaria integrifolia, MURR. (fam. Scrophulariaceae)From the leaves of Calceolaria integrifolia, a plant often used in horticulture. partially racemic (-)-dunnione (1) has been isolated. This seems to be the first record of its occurrence outside the family Gesneriaceae, where it previously has been found in two species as the (+)-enantiomer.
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    URL: http://dx.doi.org/10.1002/hlca.19770600324
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    Eine chiral ökonomischeDie Autoren bezeichnen diejenigen Totalsynthesen als chiral ökonomisch, die eine totale Transformation des achiralen Ausgangsmaterials zum angestrebten Enantiomere erlaube. Vgl. dazu: [1] [2] [3]. Totalsynthese von (R)- und (S)-Muskon via EpoxysulfoncyclofragmentierungIn memoriam Prof. Dr. Dr. h.c. Hans Schmid (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 925-944 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A chiral economic synthesis of (R)- and (S)-muscone using the cyclofragmentation of epoxysulfonesStarting with isobutyric acid (2) and using a microbiological oxidation with pseudomonas putida (S)-β-hydroxy-iso-butyric acid (3) has been prepared. From this /pseudosymmetrical: (see text) intermediate the two enantiomeric bromo derivatives 8 (R) and 20 (S) have been synthesized (cf. scheme 4) by altering the sequence of the reactions (cf. scheme 3). A Grignard reaction starting from the two bromo compounds 8 and 20 and from cyclododecanone 1 produced after hydrogenolysis the two enantiomeric dialcohols 9 and 21 (1 + 8 → 9, 1 + 20 → 21, cf. scheme 5). The subsequent transformations led to the two enantiomeric olefin derivatives 12 and 24. Oxidation of 12 with peracid produced a mixture of the two epoxy-sulfones 13 and 14 (cf. scheme 6). The olefin-derivative 24 was oxidized to the corresponding mixture of 25 and 26. A one pot cyclofragmentation (cf. [4] and scheme 6) produced a mixture of (E)- and (Z)-3-methylcyclopentadec-4-en-1-one (13 + 14 → 15 + 16, 25 + 26 → 27 + 28). The final hydrogenation led to natural (R)- and unnatural (S-muscone (3-methylcyclopentadecanone). The achiral starting material has been transformed to the desired optically active target products without loss of material with undesired absolute configuration. The authors used the notion of chiral economic synthesis to characterize synthetic sequences with the above mentioned features.
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    URL: http://dx.doi.org/10.1002/hlca.19770600323
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    13C-NMR. Spectra, Structure and Reactivity of Cyclic Oxocarbons13C-NMR. Spectroscopy, Part XVII; for Part XVI see [1].In memory of the late Prof. Hans Schmid (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 948-958 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The structures of cyclic polyketones, their hydrates and reduction products were studied in different solvents by 13C-NMR. spectroscopy. In dimethylsulfoxide solution rhodizonic acid (1), croconic acid (2) and squaric acid (3) exhibit signal averaging. In anhydrous tetrahydrofuran 1 and 2 could be observed as non-dynamic species. The spontaneous reactions of dodecahydroxycyclohexane (5) and decahydroxycyclopentane (‘leuconic acid’) (6) and the sequence of formation of ring-contracted products were investigated. Key intermediates could be clearly identified which support the mechanism proposed earlier involving a benzylic acid type rearrangement followed by decarboxylation and subsequent redox reactions.
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    URL: http://dx.doi.org/10.1002/hlca.19770600325
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    Hormone-Receptor Interactions. Carboranylalanine (Car) as a Phenylalanine Analogue: Reactions with Chymotrypsin (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 959-963 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to test the effects of the replacement of phenylalanine by carboranylalanine (Car) in biological ligand-acceptor interactions, Z · Ala-Ala-Car · OH (1) and Ac · Car · OEt (2) were synthesized and their reactions with chymotrypsin studied. The two compounds proved to be good inhibitors with K(i) values of 3 · 10-4M (1) and 8.6 · 104M (2); the K(i) of Z · Ala-Ala-Phe · OH (1a) is 1 · 10-3M. The inhibition constants were determined by a new photolytic technique, inhibition of photoaffinity labelling by Z · Ala-Ala-Phe(pN3) · OH. Ac · Car · OEt is not hydrolysed by chymotrypsin. The findings indicate that the carboranyl group can interact with the ‘phenyl recognition site’ of the enzyme to produce the binding that is characteristic of aromatic amino acid residues. However, some kind of distortion in the region of the ‘mechanistic site’ must be postulated in order to account for the failure of hydrolysis. Some possible effects of the replacement of aromatic amino acids by Car in peptide hormones on hormone-receptor interactions are discussed.
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    URL: http://dx.doi.org/10.1002/hlca.19770600326
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    1,3-Cyclobutandionderivate aus Keten (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 975-977 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,3-Cyclobutanedione derivatives from keteneThe dimerisation of ketene leads mainly to the methylidene-β-lactone ‘Diketene’ 2c. It is shown, that also a small amount of the symmetrical dimer, 1,3-cyclobutadione 1c is produced, which under the reaction conditions is acetylated to 3-acetoxycyclo-butenone (5).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600328
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    Synthesis of 4-(4′-Methyl-2′-oxo-cyclohex-3′-en-1′-yl)-pentanal and its Conversion into Derivatives of Spiro[4.5]decane and of 1,6,7,7a-Tetrahydro-2H-indene (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 964-974 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthese von 4-(4′-Methyl-2′-oxo-cyclohex-3′-en-1′-yl)-pentanal und dessen Umwandlung in Spiro[4.5]decan- und 1,6,7,7a-Tetrahydro-2H-inden-DerivateEs wird die Synthese von 4-(4′-Methyl-2′-oxo-cyclohex-3′-en-1′-yl)-pentanal als ein (1:1)-Gemisch von zwei Diastereoisomeren 10A und 10B auf folgendem Weg beschrieben: Die Umsetzung des Grignard-Reagens von 1,1-Äthylendioxy-3-brom-propan (2) mit 2-Methoxy-4-methyl-acetophenon (1) ergab 1,1-Äthylendioxy-4-hydroxy-4-(2′-methoxy-4′-methyl-phenyl)-pentan (3), welches sich mit methanolischer Salzsäure in 2-Methoxy-5-(2′-methoxy-4′-methyl-phenyl)-5-methyl-tetrahydrofuran (7A,B) umwandeln liess. Durch Birch-Reduktion von 7A,B wurde 4-(2′-Methoxy-4′-methyl-cyclohexa-1′,4′-dien-1′-yl)-pentan-1-ol (8), und danach durch milde Hydrolyse 4-(4′-Methyl-2′-oxo-cyclohex-3′-en-1′-yl)-pentan-1-ol (9A,B)2 erhalten. Oxydation von 9A,B lieferte schliesslich den erwähnten Keto-aldehyd 10A,B. Einige Produkte von Nebenreaktionen, nämlich 4, 5, 11, 12 und 13A,B, sind auch beschrieben.Der Keto-aldehyd 10A,B liess sich in ein Gemisch, bestehend aus drei Diastereo-isomeren A, B und C von 1-Hydroxy-4,8-dimethyl-spiro[4.5] dec-7-en-6-on (15) und aus zwei Diastereoisomeren A und B von 1,5-Dimethyl-1,6,7,7a-tetrahydro-2H-inden-3-carbaldehyd (14), umwandeln. Für diese aldolartigen Cyclisierungen wurden vier verschiedene Methoden verwendet: (a) Stehenlassen in Tetrachlorkohlenstoff-lösung, (b) Behandlung mit etwas Trifluoressigsäure in Chloroformlösung, (c) und (d) Schütteln einer Ätherlösung mit wässeriger Salzsäure oder Natronlauge. Oxydation von 15A und 15C lieferte eines der Diasteroisomeren von 4,8-Dimethyl-spiro[4.5]-dec-7-en-1,6-dion (16A), und Oxydation von 15B führte zum anderen (16B).
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    Synthese von Fulvenen über 1-Chloralkyl-acetate18. Mitt. über Fulvene und Fulvalene. 17. Mitt. siehe [1].Über einen Teil der Arbeit wurde kurz in [2] berichtet. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1061-1072 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of fulvenes via 1-chloroaklyl-acetatesThe synthesis of fulvenes (5) via l-chloroalkyl acetates (3) is extended to 6-alkyl-fulvenes with branched side-chains, to 6-phenylfulvene (5f) and 6-(2-furyl)fulvene (5g), as well as to 6-vinylfulvenes (5h and 5i) containing chlorine and acetoxy-substituents in ω-position. The reaction is carried out at low temperature under water-free conditions. The purification of the reaction products is simple. - An improved procedure for the preparation of pure fulvene (5a, R=R′=H) is reported.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19770600331
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  • 84
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    Aktivierte Chinone: Substitution von Azulenen, Benzofuran und Indolen durch 2-Methoxycarbonyl-1,4-benzochinon. Regiospezifische Synthesen von Polymethoxy-fluorenonen und eine neue Synthese des 2,6-Dihydro-naphtho[1,2,3-cd]indol-6-on-Systems (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1033-1060 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Activated quinones: substitution reactions by methoxy-carbonyl-1,4-benzoquinone of azulenes, benzofuran and indoles; regiospecific syntheses of polymethoxy-fluorenones; a new synthesis of the 2,6-dihydro-naphtho[1,2,3-cd]indol-6-one system.We present new electrophilic substitution reactions of azulenes and 5-membered heterocyclics by methoxy-carbonyl-1,4-benzoquinone. Hydroquinones 3a and 5 are prepared from azulene, and 3b from guaiazulene (see Scheme 1). Benzofuran undergoes α- and β-substitution (hydroquinones 9 10) (see Scheme 2). Only β-substitution is observed with indole (hydroquinone 20) (see Scheme 4). After methylation, saponification and intramolecular acylation of the substituted indoles 22c, 22d, derivatives of 2,6-dihydro-naphtho[1,2,3-cd]indol-6-one have been obtained. Spectral data prove the presence of the methylidenequinone tautomer. By protonation or alkylation at the carbonyl group of 23, the violet, highly delocalized 16π-electron systems 25 are generated. Analogously, polymethoxy-fluorenones have been prepared from methoxylated diphenylquinones 15 (see Scheme 3). They also are transformed by protonation and alkylation to the highly coloured and delocalized 12 π-electron systems 18. By contrast, anthracene is not substituted by methoxycarbonyl-1,4-benzoquinone, but undergoes cycloaddition to the triptycene derivative 1 (see Scheme 1). A summary is presented of previously described reactions of activated quinones.
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    URL: http://dx.doi.org/10.1002/hlca.19770600330
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  • 85
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    Stereoelectronic Properties, Stereospecificity and Stabilization of α-Seleno Carbanions. An ab initio StudyStereoelectronic Effects, Part 6; Part 5, see [2]. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1239-1246 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An ab initio study of α-seleno carbanions show that they are subject to appreciable polarization and stereoelectronic effects. Like in α-thia carbanions, the equatorial e forms are more stable than the axial a forms, one of the stabilizing contributions being the conformation dependent (C-lone pair, σ* Se—Z) interaction. The carbanion stabilizing effect of the α-Se atom is about 3 kcal/mol larger than that of the sulfur analog. As in the case of the sulfur no specific effect of the d orbitals is found.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19770600413
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    Isomerization of the Radical Anions of 6a-ThiathiophthenesIn the IUPAC notation, 6a-thiathiophthene, (I(H)), is [1,2]dithiolo[1,5-b][1,2]dithiole. An alternative trivial name for I(H) is 1,6,6a-trithiapentalene. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1220-1225 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The radical anions of 6a-thiathiophthenes ([1,2]dithiolo[1,5-b] [1,2]dithioles), I(R), convert into those of 4H-thiapyran-4-thiones, III(R), via cis-trans isomerization. The reaction is slowed down when the size of the substituent R in the 2,5-positions of 6a-thiathiophthene increases, and it is prevented by the introduction of a 3,4-polymethylene bridge. The primary and the secondary radical anions, I(R)\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document} and III(R)\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document}, respectively, exhibit very similar hyperfine splitting patterns. E.g., in the case of the unsubstituted 6a-thiathiophthene, I(H), and 4H-thiapyran-4-thione, III(H), the proton coupling constants are aH2,5=6.72 and aH3,4=1.73 Gauss for I(H)\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document}, and aH2,6=6.35 and aH3,5=2.07 Gauss for III(H)\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document}. In contrast to I(H)\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document}, cis-trans isomerization could not thus far be proved to occur with its 1,6-dioxa-analogue, IV(H)\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document}, since no ESR. spectrum of the radical anion of 4H-pyran-4-thione, V(H), was detected upon reduction of IV(H).
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    URL: http://dx.doi.org/10.1002/hlca.19770600410
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  • 87
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    Diterpenoide Drüsenfarbstoffe: Coleon L, ein neues Diosphenol aus Coleus somaliensis S. MOORE; Revision der Strukturen von Coleon H, I, I′ und K (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1233-1238 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Leaf-gland Pigments: Coleon L, a New Diosphenolic Compound from Coleus somaliensis, S. MOORE; Revision of the Structures of Coleon H, I, I′ and KFrom leaf-glands of C. somaliensis a new, highly oxidized diosphenolic hydroquinone belonging to the abietane series was isolated in minute quantities. The new compound, coleon L (4c; C24H30O10), is very labile and transformed into its tautomer coleon K (5d) on standing in solution. 1H-NMR. spectra of coleon L showed clearly that the points of attachment of the two acetoxy groups are at C(3) and C(16) contrary to the positions expected from our previously published structure 3 for coleon K. Application of a recently elaborated conversion of trans-A/B-6,7-diketones of type 5 into the cis-isomers 6 allowed to assign unambiguously the β-configuration to the hydroxyl group at C(3) using pyridin induced solvent shifts. This confirmed structure 4c and 5d for coleon L and K, respectively. Based on similar reasons, the configuration at C(3) of coleon H, I and I′ had to be revised, the structures of these coleons being 4b, 5b and 5c, respectively.
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    URL: http://dx.doi.org/10.1002/hlca.19770600412
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    The ESR. Spectrum of the Diphenylcyclopropenone Radical Anion (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1226-1232 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ESR. spectrum of the relatively unstable radical anion of diphenylcyclo-propenone (II) has been observed upon electrolytic reduction of II in N,N-di-methylformamide and 1,2-dimethoxyethane. Simple MO models account well for the π-spin distribution and for the restricted rotation of the phenyl substituents in II\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document}. A rather facile loss of a CO molecule by II\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document} results in formation of the radical anion of tolane (diphenylacetylene; III). No ESR. spectra could be obtained for the radical anions of dialkylcyclopropenones which are even shorter-lived than II\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document}, although decay by decarbonylation seems to be less favoured with them than with II\documentclass{article}\pagestyle{empty}\begin{document}$ ^{\ominus \atop \dot{}} $\end{document}. In presence of air, electrolytic reduction of either II or its dimethyl and di-t-butyl analogues yields the correspondingly disubstituted semidione anions.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19770600411
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  • 89
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    Reaktionen mit γ-Chloracetessigesterderivaten (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1256-1261 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions with derivatives of γ-chloroacetoacetic acidEthyl γ-chloroacetoacetate reacts with ammonia to give ethyl β-amino-γ-chloro-crotonate; with aniline, however, β-anilino-crotonic acid γ-lactone is formed. The reaction of ethyl α-cyano-γ-chloro-acetoacetate with arylamines yields 1-aryl-2-amino-3-ethoxycarbonyl-pyrrolin-4-ones.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19770600415
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  • 90
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    Die Struktur von Cyclosporin CHerrn Prof. C. A. Grob zum 60. Geburtstag gewidmet (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1247-1255 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Structure of Cyclosporin CThe structure of cyclosporin C (2), a minor antifungal metabolite from Trichoderma polysporum (Link ex Pers.) RIFAI has been elucidated. Hydrolytic cleavage and spectroscopic evidence show that cyclosporin C is a neutral oligopeptide of 11 amino acids linked together in a 33-membered ring. Cyclosporin C (2) differs from the main metabolite cyclosporin A (1) [2] [4] only by containing L-threonine in the place of L-α-aminobutyric acid as has been shown by the conversion of 2 into 1. 13C-NMR. spectra and study of molecular models suggest that cyclosporin C (2) has the same molecular conformation as 1, which is best described as a twisted β-pleated sheet held together in a conformationally stable form by intramolecular hydrogen bonding.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19770600414
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    Einbauversuche mit (3H und 14C)-doppelmarkiertem Farnesol in Cantharidin. 5. Mitteilung zur Biosynthese des Cantharidins4. Mitt.: siehe [1]. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1262-1272 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Incorporation experiments with (3H and 14C) doubly labelled farnesols into cantharidinAfter injection of 11′, 12-[3H]-7-[14C]-farnesol or 11′, 12-[3H]-5,6-[14C]-farnesol, the 3H-label is located specifically in the C(9)-methyl-group of cantharidin, whereas the 14C-labelling pattern follows an incorporation via acetic acid (Scheme 4). C-Atoms 5, 6 and 7 from the middle part of the farnesol molecule are utilized for cantharidin biosynthesis to an extent that is about 2.1-11% of the incorporation rate of the methyl groups C(11′) and C(12), depending on the position of the 14C-label in farnesol. These results confirm our earlier hypothesis [1] that the C10-molecule cantharidin is biosynthesized from the C15-precursor farnesol which is cleaved between C(1)-C(2), C(4)-C(5), and C(7)-C(8). The synthesis of 7-[14C]-farnesol and of 5,6-[14C]-farnesol is described.
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    URL: http://dx.doi.org/10.1002/hlca.19770600416
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    Synthese und NMR.-Spektren von neuartigen Lanthanoid-Kobalt-Sandwichkomplexen (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1296-1303 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and NMR. Spectra of Novel Lanthanide-Cobalt Sandwich CompoundsThe reaction of [(C5H5)Co{P(O)(OR)2}2{P(OH)(OR)2}] (3, R = CH3, C2H5) with lanthanide(III) compounds yields the cationic trinuclear complexes [{(C5H5)Co[P(O)(OR)2]3}2Ln]⊕X⊖ (2, R = CH3, C2H5; Ln = La, Eu, Pr; X = BF4, BPh4). According to thermogravimetric and NMR. studies these compounds do not contain additional coordinated water molecules. It is therefore supposed that the central lanthanide ion has a regular sixfold coordination of phosphoryl ligands. The 31P- and 1H-NMR. spectra of 2 (R = CH3; Ln = La, Eu, Pr) and 3 are discussed. It can be shown that the Fermi contact shift as well as the coordination shift make significant contributions to the observed lanthanide induced shift of the cyclopentadienyl signal.The dominating influence of the Fermi contact interaction on the 31P chemical shift is in accord with theoretical considerations and comparable experimental values. The temperature dependence of the proton chemical shifts of 2 (R = CH3; Ln = Eu) is also discussed.
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    URL: http://dx.doi.org/10.1002/hlca.19770600418
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    Stereoselektivität und Reaktivität bei der 1,3-dipolaren Cycloaddition chiraler N-(Alkoxyalkyl)nitroneHerrn Prof. Dr. R. B. Woodward zum 60. Geburtstag gewidmet (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1273-1295 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Stereoselectivity and Reactivity in the 1,3-Dipolar Cycloaddition of Chiral N-(Alkoxyalkyl)nitronesThe stereoselectivity in the reaction of hydroxy-oxime 1 with acetaldehyde and methyl methacrylate yielding the diastereomeric isoxazolidine-ribosides 9-12 was determined to be 93%. The predominant adducts 9 and 10 were cleaved to the diastereomeric isoxazolidines 19 and 20, respectively, which upon oxidation gave the same optically active 2-isoxazoline 21, thus demonstrating the participation in the cycloaddition of both (E/Z)-isomeric nitrones 13 and 14. Based upon comparison of the optical rotations, the isoxazolidines 7, 8, 19 and 20 and the 2-isoxazolines 21 and 22 possess the same chirality, found to be R by correlating 7 with (+)-(S)-citramalic acid. - Since the hydroxy-oximes 1 and 36 showed the same stereo-selectivity in the reaction with formaldehyde and methyl methacrylate, the trityl group of 1 does not influence the stereoselectivity in the cycloaddition. The hydroxyoxime 38 led in the same type of reaction to the isoxazolidines 7, 8, 19 and 20 possessing (S)-chirality, the stereoselectivity (79-95%) being similar to the one observed with 1 (67-95%). The explanation of this stereoselectivity is based upon a stereoelectronic effect in the transition state of the cycloadditions (kinetic anomeric effect). As predicted, the N-(alkoxyalkyl)nitrones showed enhanced reactivity in the cycloaddition with unactivated olefins (leading to 47, 48, 50 and 51). The importance of exo vs. endo approach of the dipolarophile was evidenced by reacting 1 with formaldehyde and methyl acrylate giving predominantly 57 with (5S)-configuration. - Use of the hydroxy-oxime 65 allows synthesis of optically active isoxazolidines with regeneration of the starting hydroxy-oxime.
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    URL: http://dx.doi.org/10.1002/hlca.19770600417
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    Die Konstitution des Loroglossins. 163. Mitt. über organische Naturstoffe162. Mitt. über Alkaloide s. [1]. (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1304-1311 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Constitution of LoroglossineLoroglossine, a characteristic constituent of orchids, is shown to be bis[4-(β-D-glucopyranosyloxy)-benzyl]-(2R, 3S)-2-isobutyl-tartrate (1). Base catalysed hydrolysis and esterification with diazomethane gave 1 mol-equiv. of dimethyl (+)-2-isobutyl-erythro-tartrate ((+)-3) and 2 mol-equiv. of a glucoside which after acetylation formed 4 identical with a synthetic sample. The structure of (+)-3 follows from the synthesis of (±)-3 by osmium tetroxide oxidation of isobutyl-maleic acid anhydride and subsequent esterification. The absolute configuration of (+)-3 was based on Horeau experiments and NMR. data of the diastereomeric mixture of its esters 15 and 16 and pure 15 with (S)-(+)- and (R)-(-)-α-phenyl-butyric acid, respectively.
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    URL: http://dx.doi.org/10.1002/hlca.19770600419
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    Diénamines hétérocycliques. III. Réexamen de la réaction de la base de Fischer avec le tétracyanoéthylène (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1312-1321 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Heterocyclic dienamines III. A re-examination of the reaction of Fischer's base on tetracyanoethyleneDepending on the order of addition, Fischer's base 5 (1,3,3-trimethyl-2-methylidene-indoline) reacts 1:1 with tetracyanoethylene to give either the tricyanovinylation product 6 or the spiro compound 7. A skeletal rearrangement of a zwitterionic intermediate can explain the formation of the spiro compound. The latter undergoes a thermal isomerization yielding by ring expansion the tetrahydroquinoléine 8. On reaction with LiAlH4 or CH3ONa 7 and 8 lead both to triazatetracycles. All structures are assigned on the basis of spectral data.
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    URL: http://dx.doi.org/10.1002/hlca.19770600420
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    Heterotricyclodecane. XXIV.Teil XXIII, vgl. [1]. 2-Aza-7-oxa-twistane (bzw. 2-Oxa-7-aza-twistane)Die nicht mit den IUPAC-Regeln übereinstimmende Numerierung (b): 2-Aza-7-oxa-twistane, Substituent an C(10) (vgl. Korrekte Nomenklatur (a): 2-Oxa-7-aza-twistane, Substituent an C(5)), wurde zwecks besserer Übersicht und Vergleichsmöglichkeit mit anderen 2,7-Dihetero-twistanen und -isotwistanen, Für eine umfassende Übersicht vgl. [2], speziell auch mit den korrekt numerierten C(10)-substituierten 2-Aza-7-oxa-isotwistanen c deshalb gewählt, weil dadurch in diesen beiden Verbindungstypen b und c, welche chemisch ineinander überführbar sind (vgl. vorliegende Arbeit), sich entsprechende Atome gleich numeriert werden Können. Dadurch erhält je das den Substituenten tragende C-Atom die Nummer 10 und je das zwischen C(10) und N(2) liegende Brückenkopfatom die Nummer 1. Beim Twistan d wurde die Doppelbindung entsprechend ihrer Herkunft aus einem C(10)-substituierten Twistan b als in Stellung 9 bezeichnet. Vollständigkeitshalber sind die der korrekten Nomenklatur (vgl. a) entsprechenden Namen der Verbindungen 10-13 und 22, 23 und 25 nachfolgend aufgeführt; 10: 5N (7)-Brom-2-oxa-7-aza-twistan; 11: N(7)-Methyl-5N (7)-2-oxa-7-aza-twistan; 12: 2-Oxa-7-aza-twist-4-en; 13: N(7)-Methyl-2-oxa-7-aza-twist-4-en; 22: N(7)-Methyl-5O (2)-acetoxy-2-oxa-7-aza-twistan; 23: N(7)-Methyl-2-oxa-7-aza-twistan-5O (2)-ol; 25: N(7)-Methyl-2-oxa-7-aza-twistan. und 2-Aza-7-oxa-isotwistane (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1435-1442 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Aza-7-oxa-twistanes (or 2-oxa-7-aza-twistanes, respectively)Die nicht mit den IUPAC-Regeln übereinstimmende Numerierung (b): 2-Aza-7-oxa-twistane, Substituent an C(10) (vgl. Korrekte Nomenklatur (a): 2-Oxa-7-aza-twistane, Substituent an C(5)), wurde zwecks besserer Übersicht und Vergleichsmöglichkeit mit anderen 2,7-Dihetero-twistanen und -isotwistanen, Für eine umfassende Übersicht vgl. [2], speziell auch mit den korrekt numerierten C(10)-substituierten 2-Aza-7-oxa-isotwistanen c deshalb gewählt, weil dadurch in diesen beiden Verbindungstypen b und c, welche chemisch ineinander überführbar sind (vgl. vorliegende Arbeit), sich entsprechende Atome gleich numeriert werden Können. Dadurch erhält je das den Substituenten tragende C-Atom die Nummer 10 und je das zwischen C(10) und N(2) liegende Brückenkopfatom die Nummer 1. Beim Twistan d wurde die Doppelbindung entsprechend ihrer Herkunft aus einem C(10)-substituierten Twistan b als in Stellung 9 bezeichnet. Vollständigkeitshalber sind die der korrekten Nomenklatur (vgl. a) entsprechenden Namen der Verbindungen 10-13 und 22, 23 und 25 nachfolgend aufgeführt; 10: 5N (7)-Brom-2-oxa-7-aza-twistan; 11: N(7)-Methyl-5N (7)-2-oxa-7-aza-twistan; 12: 2-Oxa-7-aza-twist-4-en; 13: N(7)-Methyl-2-oxa-7-aza-twist-4-en; 22: N(7)-Methyl-5O (2)-acetoxy-2-oxa-7-aza-twistan; 23: N(7)-Methyl-2-oxa-7-aza-twistan-5O (2)-ol; 25: N(7)-Methyl-2-oxa-7-aza-twistan. and 2-aza-7-oxa-isotwistanes
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600435
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  • 97
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    Generation and Reactions of Tetrasubstituted N-Lithiomethyl-succinimides (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1459-1471 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Of the isoelectronic 6-electron systems 1a, 1b, 1c (Table 1) the deprotonated amides 2 might be useful derivatives for amine acidification (eq. (1)) if the carbonyl group is sterically protected as shown in 3. The tetrasubstituted succinimides 4, 5, 7, 8 and 9 (diacylamines) undergo the reactions (b), (c) and (d) of Scheme 1 with various bases. Besides deprotonation, the ‘self addition’ to give dimers 4b, 5b, 8b and 9b is the most prominent transformation (Table 2). Only in 9 is the steric hindrance to carbonyl addition large enough to get the lithiomethyl-succinimides 9c in 80% yield (sec.BuLi/THF/HMPT/-100°) as evidenced by derivatization with alkyl halides, aldehyde, ketones, methyl benzoate, and chloro trimethylsilane (→9d - 9j, Table 3). The possible structures and bonding descriptions for 9c which ‘decomposes’ above -40° are discussed; the acidity of the precursor 9 is shown by equilibration studies to be comparable with that of diphenylmethane.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600502
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  • 98
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    Electronic Resource
    Electrochemical Reduction of Cyclohex-2-enones (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1472-1477 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electrochemical reduction of the cyclohex-2-enones 1a-1e (mercury cathode, CH3CN, Bu4NBF4) was studied by means of cyclic voltammetry, d.c. polarography, coulometry and chemical product analysis. Compounds 1a-1c give a mixture of the hydrodimers 4 and 5 via formation of the radical anion 2 by an irreversible one electron transfer, followed by protonation and dimerization of the allylic radical 3. The 6-halocyclohex-2-enones 1d and 1e exhibit two distinct reduction waves. The first corresponds to an irreversible two electron transfer with formation of the halide anion and the enolate anion 6 which gives 1b by protonation. The second wave corresponds to a quasi-reversible one electron transfer to 6 to afford the radical dianion 7 (Scheme 2).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600503
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  • 99
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    Electronic Resource
    Zum basenkatalysierten H/D-Austausch des acetylenischen Wasserstoffatoms in aromatischen Alkinylverbindungen (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1478-1486 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Base-Catalysed H/D-Exchange of the Acetylenic Hydrogen Atom in Aromatic Alkynyl CompoundsH/D-exchange rates for a number of compounds of the general type 1 (X = p-CH3O, m-CH3O, p-CF3, m-CF3, p-CH3, p-Cl, H; Z — O, NH, CH2) were determined in N-methyl-pyrrolidine (NMP)/D2O mixtures at 25° (see Table 1).It is shown that the log k values of the H/D-exchange correlate nicely (r = 0.995) with the chemical shift of the acetylenic proton in 1. Thus, the H/D-exchange rate is given by log k (min-1) = 2.91 · δ (ppm) - 7.79 for the NMP/D2O mixture at 25°.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600504
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  • 100
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    Electronic Resource
    Isomerism and Protonation of α-Diazocarbonyl Compounds. A Molecular Orbital Study (1977)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 60 (1977), S. 1487-1495 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: CNDO/2, MINDO/3 and ab initio molecular orbital calculations are used in a study of conformational isomerism, protonation site and mechanism of protonation of the title compounds.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19770600505
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