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  • 1965-1969  (2,005)
  • Physics  (1,849)
  • Cat  (55)
  • Psychopharmacology  (37)
  • Electron Microscopy  (32)
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  • 1
    Electronic Resource
    Electronic Resource
    Die Bestimmung der intestinalen Resorption von Herzglykosiden durch Messung der3H-markierten Glykoside im Portalvenenblut und in der Darmlymphe bei Katzen (1969)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 264 (1969), S. 406-419 
    Details
    ISSN: 1432-1912
    Keywords: Intestinal Absorption ; Cardiac Glycosides ; Blood of Portal Vein ; Intestinal Lymph ; Cat ; Intestinale Resorption ; Herzglykoside ; Portalvenenblut ; Darmlymphe ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The cardiac glyoosides digitoxin, ouabain, digoxin and peruvosid labelled with3H were injected into tied intestinal loops of anaesthetized cats in situ. The absorbed glycosides were measured in the blood of the portal vein and in the intestinal lymph. At the same time the3H-activity was measured in the blood of the peripheral circulation, in the bile and in the urine. 2. Calculation of the amount of glycosides totally absorbed from the3H-concentration in the blood of the portal vein and the circulation volume (bubble-flow-meter) gave the following absorption rates as a percentage of the administered dose per hour: digitoxin 56%, digoxin 42%, peruvosid 26% and ouabain 10%. 3. The amount of glycosides passing into the lymph during 1 hour was found to be only 0.006 to 0.02% of the amount offered. In lymph3H-activity cannot be measured earlier than 5 min after the administration of the labelled glycosides. The3H-concentration in the lymph did not equal that measured in the blood of the peripheral circulation until at least 1 hour after the administration and always remained below the3H-concentration of the blood in the portal vein. This proportion remained unchanged even if digitoxin was administered as an emulsion in oil instead of an aqueous solution. From the time course of3H-concentration it might be concluded that the glycosides do not pass directly to the lymph after absorption but indirectly by way of the blood. 4. The amount of glycoside excreted in the bile is for peruvosid 15,5% of the amount absorbed, for ouabain 1,9%, for digoxin 1,4% and for digitoxin 0,8%. The3H-activity excreted in urine is very small and can be disregarded. 5. Chromatographic analyses of the bile revealed, that in the case of digoxin, 4/5 of the amount excreted were unchanged, in the case of digitoxin and ouabain 2/3 and in the case of peruvosid only 1/4. In the lumen of the tied intestinal loops and in the tissue of the small intestine the glycosides were hardly metabolised.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01002379
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  • 2
    Electronic Resource
    Electronic Resource
    Verbesserung der Resorption von Helveticosid und Helveticosol durch Substitution der Hydroxylwasserstoffe an der Digitoxose (1969)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 262 (1969), S. 73-86 
    Details
    ISSN: 1432-1912
    Keywords: Strophanthidine Derivatives ; Toxicity ; Absorption ; Guinea-Pig ; Cat ; Strophanthidinderivate ; Toxicität ; Resorption ; Meerschweinchen ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurde die Wirksamkeit verschiedener Ester und Äther von Helveticosid und Helveticosol bei i.v. und intraduodenaler Zufuhr an Katzen und Meerschweinchen geprüft. 1. Bei i.v. Dauerinfusion waren Helveticosol und seine Derivate bei Meerschweinchen etwa doppelt so wirksam wie die analogen Helveticosidverbindungen. Bei der Katze bestand kein Unterschied. Die Monomethyläther Cymarin und Cymarol waren gleich oder sogar stärker wirksam, alle übrigen Derivate deutlich schwächer als die Ausgangssubstanzen. 2. Die tödlichen Dosen bei intraduodenaler Injektion lagen beim Meerschweinchen für einige Substanzen in gleicher Größenordnung oder niedriger als die Titer bei i.v. Infusion. Diese hohe enterale Wirksamkeit kann bei Helveticosid und seinen Derivaten durch eine Reduktion zu dem wirksameren Helveticosol, bei Estern außerdem durch eine Hydrolyse zu wirksameren Glykosiden vorgetäuscht werden. 3. Bei intraduodenaler Infusion an Katzen waren alle geprüften Ester und Äther wirksamer als Helveticosid und Helveticosol. Die aus dem Verhältnis der toxischen Dosen bei i.v. und intraduodenaler Infusion berechnete enterale Wirksamkeit lag zwischen 20 und 50%. 4. Unterschiede in der Dauer der intraduodenalen Infusion bei Katzen lassen sich berücksichtigen, wenn man von der theoretischen Annahme einer exponentiellen und vollständigen Resorption ausgeht und die Halbwertszeit für die Resorption berechnet. Die minimale Resorptionsgeschwindigkeit lag bei einigen Derivaten in gleicher Größenordnung wie bei Digoxin und Digitoxin. Es wird auf den Unterschied zwischen der auf Grund der pharmakologischen Wirkung bestimmten relativen enteralen Wirksamkeit und der Resorptionsquote hingewiesen. Letztere ist für die Verläßlichkeit der therapeutischen Wirkung eines Glykosids bei oraler Gabe maßgebend.
    Notes: Summary The efficacy of several esters and ethers of Helveticosid and Helveticosol was assayed by intravenous and intraduodenal administration to cats and guinea-pigs. 1. In guinea-pigs, Helveticosol and its derivatives were approximately twice as active on intravenous infusion as the analogous derivatives of Helveticosid; in cats there was no significant difference. The monomethylethers Cymarin and Cymarol were equally or slightly more potent, all other derivatives were weaker than the original compound. 2. In guinea-pigs the lethal doses of some compounds on intraduodenal injection were equal to or even lower than those on intravenous infusion. This may partly be accounted for by a reduction of Helveticosid and its derivatives to the more potent Helveticosol analogues, partly by a hydrolysis of the esters, yielding compounds of higher activity. 3. On intraduodenal infusion in cats, all the investigated esters and ethers were more active than Helveticosid and Helveticosol. The relative enteral activity calculated from the ratio of the toxic doses on intravenous and intraduodenal infusion varied between 20 and 50%. 4. Due to a delayed absorption from the gastrointestinal tract, the toxic dose falls with a reduced speed of intraduodenal infusion. Assuming an exponential and complete absorption, the half time of absorption was calculated. For some of the compounds investigated, the speed of absorption was comparable to that of Digoxin and Digitoxin. The difference between the relative enteral activities determined by comparing equiactive doses on enteral and parenteral administration and the percentages of the glycosides which are absorbed from the gastrointestinal tract is pointed out. The latter is of prime importance for obtaining reproducible effects after enteral administration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00536819
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  • 3
    Electronic Resource
    Electronic Resource
    Quantitative Untersuchungen an Gliazellen im Corpus callosum wachsender Katzen nach Perfusions- und Immersionsfixierung (1969)
    Springer
    Anatomy and embryology 128 (1969), S. 222-234 
    Details
    ISSN: 1432-0568
    Keywords: Postnatal development ; Fixation ; Neuroglia ; Corpus callosum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Gehirne von Tieren aus 4 verschieden alten Würfen junger Katzen wurden teils lebensfrisch durch Perfusion, teils nach 24 Std durch Immersion fixiert und für Vergleichsuntersuchungen in Paraffin eingebettet. Bei Betrachtung der Gliazellen des Corpus callosum ergab sich: 1. Nach Perfusionsfixierung sind die Kerne der Gliazellen groß und elliptisch. Sie sind wasserklar und haben eine scharf gezeichnete Chromatinstruktur. Nach Immersionsfixierung 24 Std p.m. sind die Kerne dagegen klein und rund, homogen dunkel gefärbt und haben ein kaum zu erkennendes Chromatingerüst. 2. Nach Perfusionsfixierung sieht man im Balken der ganz jungen Tiere zahlreiche Mitosen. Sie fehlen bei den durch Immersion fixierten Geschwistertieren desselben Wurfes. 3. Die nach verschiedener Fixierung beobachteten Unterschiede in der Form der Gliazellkerne werden durch Messungen der Quer- und Längsachsen erfaßt.
    Notes: Summary In four litters of young cats, some of the brains were fixed by perfusion and the others by immersion. The material was embedded in paraffin and the neuroglia was investigated in sections through the corpus callosum. It was found that: 1. After fixation by perfusion the nuclei of the glia cells are large and elliptic. The caryoplasm is clear and there is a distinct structure of the chromatin. After fixation by immersion the nuclei of the same cells are small and round. The caryoplasm is dense and the structure of the chromatin is not clearly visible. 2. After fixation by perfusion mitotic figures are present. They are absent in the brains fixed by immersion. 3. Following different fixation, there are differences in the shape of the nuclei of the glial cells. These differences have been investigated in detail by measuring the diameters of the nuclei.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00521281
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  • 4
    Electronic Resource
    Electronic Resource
    Über die Gefäßversorgung des Corpus callosum der Katze (1969)
    Springer
    Anatomy and embryology 128 (1969), S. 28-39 
    Details
    ISSN: 1432-0568
    Keywords: Arterial supply ; Corpus callosum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 27 Katzen beiderlei Geschlechts wurde die Blutversorgung des Corpus callosum untersucht. Dabei wurden folgende Befunde erhoben: Der Balken der Katze wird im Bereich des Rostrum und Genu sowie im vorderen und mittleren Truncuabschnitt aus der Arteria cerebri anterior versorgt und zwar über Äste, die den Arteriae pericallosae und den Arteriae genu corporis callosi entstammen. Diese Äste wurden als Arteriae callosi superiores und inferiores bezeichnet. Lediglich im hinteren Truncusabschnitt und im Splenium erfolgt die Versorgung neben Ästen der A. pericall. auch über solche der Arteriae cerebri mediae und posteriores. Die Blutgefäße treten dolchartig in den Balken ein, teilen sich dann baumartig weiter auf und gehen in ein Capillarnetz über, das in Richtung des Nervenfaserverlaufes ausgezogen ist. Auf in der Literatur bereits bekannte, aber oft vernachlässigte Besonderheiten der Arteria carotis interna und des Circulus arteriosus wird hingewiesen.
    Notes: Summary In investigations on 27 cats of both sexes, the arterial supply of the corpus callosum was studied. The findings are as follows: In the region comprising rostrum and genu as well as in the fore and middle trunk sections, blood supplied by branches of the arteriae pericallosae and the arteriae genu corporis callosi which originate from the arteria cerebri anterior. These branches were designated arteriae callosi superiores and inferiores. However, in the posterior section of the trunk and in the splenium the blood is supplied by branches of the aa. pericall. and, in addition, by branches of the arteriae cerebri media and posteriores. The blood vessels penetrate the corpus callosum in bayonet fashion, then arborise and finally become a capillary network which is elongated in the direction of the course of the nerve fibres. Attention is drawn to peculiarities of the arteria carotis interna and the circle of Willis which, although known in the literature, are rarely referred to.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00522492
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  • 5
    Electronic Resource
    Electronic Resource
    Étude d'une nouvelle observation de «Nemaline Myopathy» (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 250-266 
    Details
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Congenital Myopathy ; Nemaline Myopathy ; Z-band Structure ; Sarcoplasmic Masses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé L'étude ultrastructurale d'une observation de «Nemaline-Myopathy» a été centrée sur les rapports structurels entre bâtonnets et stries Z normales dans différentes conditions de fixation. L'aspect des stries Z, en section transversale, varie en effet avec la fixation: réseau de ponts «obliques» (par rapport à l'alignement quadratique régulier des terminaisons des filaments fins) après fixation osmiée, réseau de ponts «transversaux», isolé ou superposé au premier réseau, après fixation aldéhydique initiale. L'aspect des bâtonnets en section transversale varie également avec la fixation; la disposition quadratique des filaments constitutifs des bâtonnets est visible après l'une et l'autre fixation, mais un réseau quadratique régulier, de 75 Å de côté, n'est clairement apparent qu'après fixation aldéhydique. Le point important est que ce dernier aspect diffère complètement du réseau «oblique» des stries Z normales, et peut être rapproché au contraire du réseau «transversal» de la strie Z obtenu après fixation aldéhydique; l'hypothèse est ainsi soulevée de la constitution des ponts dans les bâtonnets aux dépens d'un seul des deux constituants morphologiques de la strie Z. La topographie des bâtonnets a été également étudiée: tantôt périphérique, au sein de masses sarcoplasmiques latérales, tantôt centrale, au sein de petits foyers de désintégration myofibrillaire. La structure des plaques motrices visibles dans les préparations était normale. La spécificité de la lésion élémentaire et l'autonomie de ce type de myopathie sont ensuite discutées.
    Notes: Summary Ultrastructural study of an observation of “Nemaline Myopathy” has been focused on structural relationships between rods and normal Z-bands in different conditions of fixation. The Z-band structure studied in transversal section, varies with the fixation: network of “oblique” (relative to the regular quadratic pattern of the thin filament endings) bridges after osmic fixation; network of “transversal” bridges, alone or associated to the first network, after aldehydic fixation. The rod structure, in transversal section, is also varying with the fixation: a quadratic disposal of the filamentary content is visible after both fixations, but a regular quadratic network, 75–85 Å side, is clearly appearent only after aldehydic fixation. This last network differs from the “oblique” network of the normal Z-band; it can be compared to the “transversal” one obtained in the Z-band after aldehydic fixation. The hypothesis that bridges in the rods are formed only by one of the two normal morphological components of the Z-band, is raised. Topography of the rods in muscle fibers has been studied: either in peripheral sarcoplasmic masses, or in small central-located foci of myofibrillar disintegration. The end-plates structure was normal. Specificity of the elementary lesion, and autonomy of that type of myopathy is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690645
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  • 6
    Electronic Resource
    Electronic Resource
    Sodium demonstration in rat cerebrum following perfusion with hydroxyadipaldehyde-antimonate (1969)
    Springer
    Acta neuropathologica 12 (1969), S. 173-182 
    Details
    ISSN: 1432-0533
    Keywords: Sodium Deposits ; Electron Microscopy ; Perfusion with Hydroxyadipaldehyde-Antimonate ; Extracellular Space
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine Modifikation der Methode zur ultrastrukturellen Darstellung von Natrium wird beschrieben, die eine Perfusion mit leicht alkalischer Mischung von Hydroxydipaldehyd, Phosphatpuffer und Kalium-Pyro-Antimonat verwendet. Im normalen Gehirn werden keine Natrium-Deposite angetroffen. Das spricht dafür, daß im Gehirn keine intraoder extracelluläre Konzentration über 150 mM vorliegt. Bei Vorliegen hoher NaCl-Konzentration sieht man ein großes, dichtes Präcipitat, das nach direkter Injektion in den extracellulären Räumen, Neuronen und Astrocyten lokalisiert werden kann. Im Mark der vergifteten Ratten findet sich ähnlich wie nach direkter Natrium-Injektion ein diskretes, gleichfalls als Natrium aufgefaßtes Präcipitat an der Oberfläche von Oligodendrogliazellen, aber nicht innerhalb dieser Zellen. Ein elektronendichtes Deposit unklarer Herkunft findet sich in den Myelinspalten, die nach akuter TET-Vergiftung auftreten. Der Wechsel in Charakter und Lokalisation dieser elektronendichten Partikel mahnt zur Vorsicht in ihrer Interpretation bei histochemischen Untersuchungsmethoden.
    Notes: Summary A modification of the technique for the ultrastructural demonstration of sodium is described which involves a perfusion with a slightly alkaline mixture of hydroxyadipaldehyde, phosphate buffer and potassium pyroantimonate. No sodium deposits are found in normal brain indicating that no intra or extracellular concentration exceeding 150 mM is present in the brain. In the presence of high concentration of NaCl, a large dense precipitate can be seen which after a direct injection can be localized to extracellular spaces, neurons and astrocytes. In the white matter of tin poisoned rats, as well as after the direct injection of sodium, a discrete precipitate, also believed to represent sodium, is noted at the surface of oligodendrocytes but not within these cells. An electron dense deposit of dubious origin is present in the myelin clefts which occur as a result of acute triethyltin intoxication. The variations in the character and localization of these electron dense particles emphasize the caution which is required in their interpretation following histochemical procedures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00692504
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  • 7
    Electronic Resource
    Electronic Resource
    Züchtung und Vermehrung von Herpes simplex-Virus in Zellkulturen vom Nervensystem (1969)
    Springer
    Acta neuropathologica 12 (1969), S. 276-299 
    Details
    ISSN: 1432-0533
    Keywords: Herpes simplex Virus ; CNS Tissue Culture ; Multiplication in vitro ; Cytopathic Alterations ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die häufig diskutierte, (Mit)beteiligung von Herpes simplex-Virus (HSV) bei bestimmten Alterationen im ZNS sowie der hohe Neutropismus des HSV führte zur Frage, inwieweit sich HSV auch in in vitro gezüchteten, spezifischen Zellen vom Nerven-system vermehren und züchten läßt, und ob sich hierbei licht-und elektronenmikroskopisch charakteristische Alterationen nachweisen lassen. Es zeigte sich, daß sich das HSV in allen verschiedenen angezüchteten spezifischen Zellen (von Plexus chorioideus des Rhesusaffen, Kaninchenspinalganglien, menschlichen Oligodendrogliomen, Meningeomen sowie fibrillären und protoplasmatischen Astrocytomen) kultivieren und vermehren läßt. Hierbei kommt es in den spezifischen Zellen nicht nur lichtmikroskopisch zu charakteristischen cytopathischen Veränderungen, sondern auch biologisch zu einer signifikanten Vermehrung des Virus in diesen Zellen. Auch elektronenmikroskopisch lassen sich viele der charakteristischen Bildungs-, Reifungs- und Ausschleusungsstadien des Virus in den Kernen und im Cytoplasma der Zellen beobachten. Die Besonderheiten der elektronenmikroskopisch erhobenen ultrastrukturellen Befunde werden ausführlich beschrieben, und die sich daraus abzuleitenden Möglichkeiten werden im Hinblick auf die biologischen Eigenheiten des HSV bei in vivo-Infektionen, aber auch im Hinblick auf die Deutung lichtmikroskopisch histochemischer und immunhistologischer Befunde nach in vivo-Infektionen mit diesem Virus ausführlich diskutiert.
    Notes: Summary The participation of herpes simplex virus (HSV) in certain alterations of the CNS has been partially questioned and frequently discussed. Therefore, the question arose whether HSV can also be cultivated and multiplied in vitro in CNS specific cells, and if so, whether characteristic alterations and structures can be observed by means of light and electron-microscopic examinations. Our data demonstrate that HSV multiplies in all different specific cells originating from plexus chorioideus of rhesus monkeys, from spinal ganglia of rabbit, from human oligodendroglioma, meningeoma as well as from fibrillar and protoplasmatic astrocytoma. Characteristic cytopathic alterations of these specific cells and significant multiplication of the virus in these cells are to be found. Many of the characteristic forms of formation, maturation and release of HSV can be seen by electronmicroscopic examinations. The particular ultrastructural data observed by electron microscopy are described in detail and the resulting possibilities are broadly discussed not only with regard to the biologic particularity of HSV in in vivo infection but also in view of the interpretations, deriving from histochemical and immunohistological data obtained by light microscopy after in vivo infection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687650
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  • 8
    Electronic Resource
    Electronic Resource
    Electron microscopic studies concerning the structural mechanism of the development of mental disturbance in experimental chronic methamphetamine poisoning (1969)
    Springer
    Acta neuropathologica 14 (1969), S. 215-225 
    Details
    ISSN: 1432-0533
    Keywords: Methamphetamine Poisoning (Artificial Psychosis) ; Synapses ; Nerve Conduction and Transmission ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Amphetaminchlorid in Mengen von 1 mg pro kg pro Tag wurde 8 männlichen Meerschweinchen ungefähr 1 Jahr lang täglich injiziert, um eine chronische Amphetaminvergiftung zu erzeugen. Bei jedem vergifteten Tier wurde die Feinstruktur des Gehirns elektronenmikroskopisch untersucht. Die Befunde waren folgende: 1. Verschmelzung der Membranen zwischen Axonen in den Nervenendigungen sowie zwischen Axonen und Dendriten wurden in der Großhirnrinde, im limbischen System, im Thalamus und Hypothalmus beobachtet; ferner wurde eine sich vom Cytoplasma bis zur Nervenendigung erstreckende Membranstruktur in diesen Hirnbereichen festgestellt. 2. Im Frontal-, Parietal-, Temporal- und Occipitalhirn sowie im limbischen System fanden sich vermehrt membranbegrenzte Vesikel im Cytoplasma der Nervenzellen und verdicktes und vermehrtes ER in den Nervenfasern. In Anbetracht klinischer Symptome der Patienten mit Amphetaminvergiftung wurde angenommen, daß die Verschmelzung von Membranen zwischen Nervenfortsätzen und das Auftreten der Membranstrukturen in allen Teilen des Nervenzellcytoplasmas vom Perikaryon bis zur Nervenendigung die wichtigsten Befunde sind, die darauf hindeuten, daß die Vergiftungsvorgänge einen wesentlichen Einfluß auf das Leitungssystem der Nerven ausüben können.
    Notes: Summary In 8 male albino strain guinea pigs, 1 mg/kg of methamphetamine HCl was injected daily for 7 months to 1 year to produce chronic methamphetamine intoxication and to study the fine structure of the brain electron microscopically. The following results were obtained: 1. Coalescence of membranes, between axons at the nerve endings and between axons and dendrites, was found in the cortex of the cerebrum and limbic system, in the thalamus and hypothalamus. Membranous structures were found in all portions of the cytoplasm of the nerve cells. 2. Within the cytoplasm of the nerve cell, coated vesicles were increased in number with hypertrophy and increase of endoplasmic reticulum within nerve fibres in the frontal, parietal, temporal and occipital regions, and in the limbic system. In view of these findings, as well as the clinical neurological symptoms in patients with methamphetamine poisoning, the coalescence of membranes between nerve processes and the appearance of membranous structures in all portions of nerve cell cytoplasm from body to nerve endings appear to represent the most important findings, they probably produce a profound disturbance in the system of nerve conduction and transmission.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685301
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  • 9
    Electronic Resource
    Electronic Resource
    The inhibition of calcium hydroxyapatite crystal growth by polyphosphonates and polyphosphates (1969)
    Springer
    Calcified tissue international 3 (1969), S. 151-162 
    Details
    ISSN: 1432-0827
    Keywords: Calcification ; Physiologic ; Phosphonic Acids ; Phosphates ; Crystallization ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé On a étudié la formation de l'hydroxyapatite de calcium cristallin à partir de solutions d'ions de calcium et de phosphate et l'inhibition de la croissance de cristaux de l'hydroxyapatite de calcium au moyen de polyphosphonates et de polyphosphates. Les polyphosphonates, éthane hydroxy-1-diphosphonate-1,1 de disodium et dichlorométhanediphosphonate de disodium, sont inhibiteurs efficaces contre la croissance de cristaux de l'hydroxyapatite de calcium. Les polyphosphates sont aussi inhibiteurs efficaces contre la croissance de cristaux de l'hydroxyapatite de calcium tant que le niveau exigé de polyphosphate intact est présent dans le système. Cependant, à cause de leur instabilité hydrolytique, qui est soulignée par une température élevée, valeur de pH basse, et certaines enzymes, la concentration du polyphosphate diminue avec le tempsin vitro, et son activité comme inhibiteur est perdue. Au contraire aux polyphosphates, les polyphosphonates sont hydrolytiquement stables. Les polyphosphonates sont chimiosorbés sur la surface des microcristallites de l'hydroxyapatite de calcium, ainsi empêchant l'occurrence d'autre croissance de cristaux semblable à l'action d'autres poisons connus de croissance de cristaux. On propose l'extension de cette action sur la formation de l'apatite et cette stabilité des polyphosphonates aux applications médicales et dentaires concernant le metabolisme pathologique de calcium et de phosphate.
    Abstract: Zusammenfassung Die Bildung des kristallinen Calciumhydroxyapatit aus Lösungen, welche Calcium- und Phosphationen enthalten, und die Hemmung der Bildung von kristallinen Calciumhydroxyapatit durch Polyphosphonate und Polyphosphate wurden untersucht. Polyphosphonate, Dinatriumäthan-1-hydroxyl-1,1-diphosphonat und Dinatriumdichloromethandiphosphonate verhindern das Kristallwachstum des Calciumhydroxyapatits. Die Polyphosphate verhindern ebenfalls das Kristallwachstum des Calciumhydroxyapatits, solange die notwendige Konzentration des nicht hydrolysierten Polyphosphats vorhanden ist. Wegen ihrer hydrolytischen Unbeständigkeit, die durch hohe Temperatur, niedrige pH und bestimmte Enzyme erhöht wird, vermindert sich jedoch die Konzentration des Polyphosphats allmählichin vitro, und ihre Hemmungsaktivität geht verloren. Im Gegensatz zu den Polyphosphaten sind die Polyphosphonate hydrolytisch beständig. Die Polyphosphonate werden an der Oberfläche der Mikrokristallite des Calciumhydroxyapatits chemisorbiert und verhindern, wie andere bekannte Kristallwachstumsgifte, auf diese Weise weiteres Kristallwachstum. Die Beständigkeit der Polyphosphonate und ihre Chemisorption an dem Apatit empfehlen ihren Gebrauch in der ärztlichen und zahnärztlichen Praxis, soweit sie den pathologischen Calcium- und Phosphatstoffwechsel betreffen.
    Notes: Abstract The formation of crystalline calcium hydroxyapatite from solutions of calcium and phosphate ions and the inhibition of calcium hydroxyapatite crystal growth by polyphosphonates and polyphosphates have been studied. The polyphosphonates, disodium ethane-1-hydroxy-1,1-diphosphonate and disodium dichloromethane diphosphonate, are effective inhibitors of calcium hydroxyapatite crystal growth. The polyphosphates are also effective inhibitors of calcium hydroxyapatite crystal growth as long as the required level of intact polyphosphate is present in the system. However, because of their hydrolytic instability, which is enhanced by high temperature, low pH, and certain enzymes, the concentration of the polyphosphate decreases with timein vitro, and its activity as an inhibitor is lost. In contrast to the polyphosphates, the polyphosphonates are hydrolytically stable. The polyphosphonates are chemisorbed on the surface of the microcrystallites of calcium hydroxyapatite and, in the manner of other known crystal growth poisons, thus prevent further crystal growth. The stability of the polyphosphonates and their chemisorption on apatite suggest their use in medical and dental applications involving pathological calcium and phosphate metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02058658
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  • 10
    Electronic Resource
    Electronic Resource
    Inhibitory and excitatory factors influencing the receptive fields of lamina 5 spinal cord cells (1969)
    Springer
    Experimental brain research 9 (1969), S. 284-306 
    Details
    ISSN: 1432-1106
    Keywords: Cutaneous receptive fields ; Spinal cord ; Cat ; Pain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Examination of cutaneous receptive fields (RFs) of lamina 5 cells in the lumbar spinal cord of decerebrate cats shows them to have three distinct zones with respect to mechanical and electrical stimulation. The mean response rate to both mechanical and electrical stimulation in zone 1 increases steadily up to the highest strengths used; in zone 2, surrounding zone 1 mainly proximally, mild stimuli reduce the mean rate, stronger stimuli increase it; in zone 3, mainly proximal to zone 2, all stimuli reduce the rate. Temporally, zone 1, electric shocks near threshold produce bursts of firing followed by inhibition. With increased stimulus strength, the bursts lengthen to a second or more. In zones 2 and 3, inhibition at all strengths is preceded at higher strengths by bursts of firing. Cold-blocking the spinal cord at lower thoracic levels reversibly increases the ongoing activity of these cells, increases the area of zones 1 and 2, and almost completely suppresses all inhibition. Stimulation of dorsal columns and threshold stimulation of distant dorsal roots inhibits ongoing and induced activity. Barbiturate decreases ongoing activity and the duration of firing produced by cutaneous electrical stimulation but does not decrease inhibition. These results are consistent with a model in which low-threshold fibres are excitatory only over a small central area of the RF of a lamina 5 cell (zone 1), high threshold fibres are excitatory over a larger area (zones 1 and 2), and low threshold fibres are inhibitory over the entire receptive field (zones 1, 2 and 3) with a slower time-course. This inhibition is tonically enhanced by descending influences in the decerebrate cat. It is suggested that the high and low threshold fibres correspond approximately to the small and large diametre fibres whose balance is the basis for the coding of pain in the theory of melzack and wall.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235240
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  • 11
    Electronic Resource
    Electronic Resource
    The lateral cervical nucleus in the cat IV. A light and electron microscopical study after midbrain lesions with demonstration of indirect wallerian degeneration at the ultra-structural level (1969)
    Springer
    Experimental brain research 7 (1969), S. 51-67 
    Details
    ISSN: 1432-1106
    Keywords: Lateral cervical nucleus ; Midbrain lesions ; Nauta method ; Ultrastructural investigation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The lateral cervical nucleus (LCN) has been studied with the light and electron microscope after midbrain lesions in kittens of different ages, and in adult cats. It has been shown that nerve cells remain within the contralateral LCN after hemisection of the midbrain. performed on 1 day old kittens. The estimated number of these remaining cells was 3–19% in the different cases. No fibers descending to the LCN from levels rostral to the midbrain could be demonstrated in adult cats with the Nauta technique. A combined Nauta and electron microscopical investigation was performed on kittens operated on at different ages and allowed to survive varying times postoperatively. At the operations the LCN-axons were transected at midbrain level. The Nauta investigation demonstrated silver impregnation of degenerating LCN-neurons on the affected side of the same type as has been described recently in other neuronal systems following axonal transection. The ultrastructural study revealed electron dense degenerating dendrites and probably also nerve cells within the LCN. The dense degenerative changes were very similar to the dense degeneration in terminal boutons following transection of parent axons. The potential value of the findings for electron microscopical research in neuroanatomy is discussed. The results in terms of connections of the LCN are discussed in the light of known anatomical and physiological data of the LCN.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236107
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  • 12
    Electronic Resource
    Electronic Resource
    Contrôle de l'activité des fibres fusimotrices dynamiques et statiques par la formation réticulée mésencéphalique chez le chat (1969)
    Springer
    Experimental brain research 9 (1969), S. 307-324 
    Details
    ISSN: 1432-1106
    Keywords: Muscle spindle ; Gamma motor control ; Mesencephalic reticular formation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Effects of repetitive stimulation of the mesencephalic reticular formation (MRF) on the static discharge and dynamic sensitivity of muscle spindle primary endings (soleus muscle) were studied in cats anaesthetized with Halothane (Fluothane). By progressive increasing the depth of anaesthesia three different fusimotor effects could be observed: 1. A static effect; the static discharge of the primary endings was strongly increased; the response to phasic stretch was decreased or remained unaltered. 2. A dynamic effect; the dynamic sensitivity of the primary endings was powerfully increased while the rate of discharge under static conditions was only slightly augmented. 3. A depressant effect; the static discharge and the dynamic sensitivity of primary endings were decreased. Repeated stimulation elicited successive static and dynamic effects. No specific regions within the MRF could be related to a particular effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235241
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  • 13
    Electronic Resource
    Electronic Resource
    Etude fonctionnelle du contrôle de l'activité des fibres fusimotrices dynamiques et statiques par les formations réticulées mésencéphalique, pontique et bulbaire chez le chat (1969)
    Springer
    Experimental brain research 9 (1969), S. 325-345 
    Details
    ISSN: 1432-1106
    Keywords: Muscle spindle ; Gamma motor control ; Reticular formations ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. During a progressive increase of Fluothane (Halothane) anaesthesia, repetitive stimulation of the mesencephalic retioular formation (MRF) produces several fusimotor effects — static, dynamic or depressant — on primary endings of soleus muscle spindles (Vedel et Mouillac-Baudevin 1969). 2. Transection of the brain immediately rostral to the site of stimulation may increase the dynamic effect but does not alter the static or the depressant effects. 3. A section of the rubrospinal tract does not modify the fusimotor effects elicited by stimulation of the MRF. 4. Transections of the spinal cord have shown that the pathways responsible for the transmission of these effects are mainly situated in the ipsilateral ventral and ventrolateral funiculi which contain the efferent fibers from the pontine reticular formation (PRF), from the bulbar reticular formation (BRF) and from the vestibular nucleus. 5. Contra and ipsilateral PRF stimulation produces the static fusimotor effect; contralateral stimulation from a small anterior region produces the dynamic effect. 6. Stimulation of the lateral part of the ipsilateral BRF elicits the dynamic effect while stimulation of the medial part elicits the static effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235242
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  • 14
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    Electronic Resource
    The lateral cervical nucleus in the cat III. An electron microscopical study after transection of spinal afferents (1969)
    Springer
    Experimental brain research 7 (1969), S. 32-50 
    Details
    ISSN: 1432-1106
    Keywords: Lateral cervical nucleus ; Spinal lesions ; Ultrastructural investigation ; Degenerating boutons ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of terminal degeneration within the lateral cervical nucleus (LCN) after transection of its spinal afferent fibers 2 days–2 years earlier is described. The degeneration after 2 days was of both the neurofilamentous and dense type. The highest number of degenerating terminals, about 15%, was found after 4–5 days. Then most of the degenerating boutons were of the dense type. The degenerating terminals had synaptic contact with cell bodies and dendrites of LCN-neurons. Removal of the degenerating boutons seemed to be effected by a phagocytic cell present in increased number compared to the normal LCN. In cases with long survival times an increase in the number of astroglial filaments was observed. In an animal where the spinal afferents to the LCN had been cut 2 years earlier a decrease in medium size of the neurons was observed. The amount of dendritic spines was also considerably smaller than normally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236106
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  • 15
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    Electronic Resource
    Inhibition in the medial geniculate body of the cat (1969)
    Springer
    Experimental brain research 7 (1969), S. 68-83 
    Details
    ISSN: 1432-1106
    Keywords: Medial geniculate body ; Inhibition ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Inhibitory activity in the cat medial geniculate body (MG) was examined by stimulating electrically and acoustically the input and output of the MG. 2. A longer and more profound depression of excitability occurs following a click-evoked potential in the MG than in the inferior colliculus (IC) in both anesthetized and unanesthetized states. Recovery is cyclic in the barbiturate MG preparation. 3. Electrical stimulation of the brachium of the inferior colliculus (BIG) evokes a field potential in the MG consisting of clearly distinguishable presynaptic and postsynaptic components. The presynaptic component recovers rapidly, while the postsynaptic component requires 100–200 msec for full recovery. This depression of excitability is localized within the MG since cortical ablation does not alter its occurrence. 4. Stimulation of the BIC mimics the effects of click stimulation on single units. Excitatory, inhibitory and reverberatory responses are evoked by the BIC shock. Suppression of single unit activity correlates with the depression of excitability following a BIC-evoked field response. 5. Cortical stimulation can evoke antidromic and trans-synaptic unit responses in the MG, as well as causing a variety of inhibitory effects and reverberation. In view of the fact that cortical ablation does not impair the recording of these responses to afferent stimuli, it is suggested that the cortical-evoked responses are at least partly mediated by antidromic conduction to MG. 6. Evidence is presented that inhibitory effects of both afferent and cortical stimulation are due to active inhibition of MG unit activity. Speculations are made as to the mechanisms producing inhibition and reverberation in the MG.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236108
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  • 16
    Electronic Resource
    Electronic Resource
    Electronmicroscopic observations on the structure of the pontine nuclei and the mode of termination of the corticopontine fibres an experimental study in the cat (1969)
    Springer
    Experimental brain research 7 (1969), S. 95-110 
    Details
    ISSN: 1432-1106
    Keywords: Electron microscopy ; Pontine nuclei ; Experimental neuroanatomy ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The electron microscopical changes occurring in the pontine nuclei following unilateral lesions of the primary sensorimotor cortex have been studied in 7 cats with a survival time from 2–23 days. A description is also given of the fine structure of the pontine regions in receipt of the fibres. These regions are shown in Fig. 1. The study shows that the boutons are practically only in synaptic contact with dendrites. The bouton density on these is only 16%. The boutons are of the en passage and terminal type, with the latter as the most common (Figs. 4a-e). The synaptic vesicles are rounded or elongated. The formaldehyde fixed material had 17.8% boutons with vesicles of the elongated type; the material fixed with a mixture of formaldehyde and glutaraldehyde had only 11.5% of such boutons. The degenerating boutons show the dark type of reaction and the majority of the corticopontine fibres are of the type shown in Figs. 4d and 4e. Astrocytes and microglial cells participate in the removal of degenerating boutons and terminal fibres. Degenerating boutons are present even at the 23 day stage and some have apparently only started to degenerate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235436
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  • 17
    Electronic Resource
    Electronic Resource
    Die Bedeutung der Vorderhirnkommissuren für die Koordination bilateraler EEG-Muster (1969)
    Springer
    Experimental brain research 7 (1969), S. 195-213 
    Details
    ISSN: 1432-1106
    Keywords: Corpus callosum ; EEG synchronization ; Homolateral sensory evoked potentials ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Spontaneous EEG-patterns and evoked potentials (EP's) of symmetrical cortical areas were recorded in chronic and acute cats before and after section of the corpus callosum, the commissura anterior and posterior and the massa intermedia. The spontaneous EEG was recorded without and with anesthesia, EP's after electrical stimulation of the fore-paws only during nembutal anesthesia. — No changes in the bilateral coordination of spontaneous and evoked EEG-patterns could be seen after commissurotomy (CT). The bilateral coherence of EEG-waves as revealed by cross-correlation is low already in the normal cats and does not change significantly after CT. The values of cross-correlation coefficients at T = ± 15 msec vary during one EEG-record between -0.25 and +0.25 in the somatosensory, suprasylvian and temporal areas (mean values slightly above 0). In the visual area occasionally positive values between 0.5 and 0.8 were seen, but also here a large variation was found in all animals and the mean values were below 0.1. No consistent phase shift between both sides was observed. EEG-patterns like spindles or arousal, still occurred together in both hemispheres after CT, the variability of their exact beginning or end was the same as in controls. Spontaneous spindles often lasted longer after section of the massa intermedia. Homolateral EP's in the somato-sensory area were still present after CT. Rhythmical afterdischarges could be restricted to the contralateral somato-sensory cortex even before CT.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239029
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  • 18
    Electronic Resource
    Electronic Resource
    Evidence for mediated transport of chloride in cat cerebral cortex in vitro (1969)
    Springer
    Experimental brain research 8 (1969), S. 219-231 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex in vitro ; Chloride transport ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The kinetics of the uptake of chloride by slices of cat cerebral cortex incubated in vitro have been studied for a wide range of concentrations of chloride and potassium in the incubation media. 1. In studies with 36Cl at a constant concentration of external K+, the rate of entry of chloride into slices of cat cerebral cortex (after equilibration with the fluid of the extracellular space) followed Michaelis-Menten kinetics with Vmax=7.7 μmoles/g/min and Km=245 mM. The kinetic data so described differ significantly from a curve describing simple diffusion (P 〈 0.02). 2. A clear dependence on concentration of K+ in the incubation medium was demonstrated. When external chloride was held constant at 6.8 mM and concentrations of potassium were varied over a range of 27–100 mM, the apparent rate of entry of chloride followed Michaelis-Menten kinetics with Vmax=0.191 μmoles/ g/min and Km=30.3 mM. 3. Under similar equilibrium conditions, the rate of influx of chloride was not statistically different from the rate of efflux, and the value for extracellular space (355 μl/g) derived by extrapolation from efflux data was of an identical order of magnitude to the value (352 μl/g) obtained from influx data. These values are essentially identical to those previously determined for chloride space of cat cerebral cortex in vivo (Bourke, Greenberg and Tower 1965). 4. The total, membrane-delimited content of chloride in cerebral cortex, as defined in these studies in vitro, was a function of the concentration of K+ in the incubation medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234250
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  • 19
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    Electronic Resource
    Studies of the development and subsequent reduction of swelling of mammalian cerebral cortex under isosmotic conditions in vitro (1969)
    Springer
    Experimental brain research 8 (1969), S. 232-248 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex in vitro ; Edema ; Fluid compartmentation ; Chloride transport ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ionic parameters of incubation media which foster both the development and subsequent reduction of swelling of slices of cerebral cortex under isosmotic conditions of incubation in vitro are described. A linear relationship between increasing chloride concentrations in incubation media and progressive swelling of tissue slices (under conditions of constant temperature and K+ concentrations and isotonicity of incubation media) is demonstrated. Subsequent reduction of chloride concentration in incubation media together with reciprocal replacement by isethionate is associated with significant and characteristic reduction in the volume of tissue swelling when all other conditions of incubation, including isotonicity of the media, are kept constant. The ionic composition of the fluid of swelling under different conditions of incubation is derived together with the ionic composition and expected transmembrane potentials of the neuronal compartment of cerebral cortex in vitro. Mechanisms involved in the development and subsequent reduction of swelling of cerebral cortex in vitro are discussed, and proposals for possible clinical applications are suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234251
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  • 20
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    Electronic Resource
    Integration konvergierender Afferenzen in der bulbären Formatio Reticularis der Katze (1969)
    Springer
    Experimental brain research 7 (1969), S. 143-157 
    Details
    ISSN: 1432-1106
    Keywords: Reticular formation ; Convergence ; Inhibition ; Cat ; Chloralose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Ein konditionierender corticaler Reiz inhibiert den somatischen Startlereflex bei Katzen unter Chloralosenarkose für eine Dauer von mehr als 200 ms. Die Interaktionen zwischen beiden Reizen laufen in der bulbären und pontinen Formatio reticularis ab. 2. Dem Startlereflex liegt eine polysynaptische Erregungsschleife zugrunde, die die bulbäre und pontine Formatio reticularis durchzieht. Die Resistenz der reticulären Neurone gegenüber repetitiver Stimulation wurde als Kriterium ihrer funktionellen Lokalisation auf dem polysynaptischen Reflexbogen gewertet. 3. Die corticale Inhibition wird im Verlaufe der polysynaptischen Erregungsschleife zunehmend stärker. Neurone, die von den Startlereflexafferenzen direkt erregt werden, werden durch den corticalen Reiz nicht inhibiert. Dies schliebt eine präsynaptische Inhibition der reticulopetalen Fasersysteme aus.
    Notes: Summary 1. The startle reflex evoked by cutaneous stimulation in cats under chloralose anesthesia is inhibited for more than 200 ms by a conditioning cortical volley. The interaction between the cutaneous and the cortical volley takes place in the bulbar and pontine reticular formation. 2. The startle reflex involves a series of reticular neurones. Resistance to repetitive stimulation has been determined to evaluate the functional localization of each neurone within this polysynaptic path. 3. Inhibition following the cortical volley becomes increasingly more effective along the course of the polysynaptic path and is completed within 5–6 ms. Reticular neurones excited directly by the spino-reticular afferents are not inhibited, thus excluding a presynaptic inhibition of the spinoreticular fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235440
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  • 21
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    Electronic Resource
    Functional organization of the vestibular afferents to the cerebellar cortex of frog and cat (1969)
    Springer
    Experimental brain research 9 (1969), S. 30-52 
    Details
    ISSN: 1432-1106
    Keywords: Climbing fibers ; Mossy fibers ; Vestibulo-cerebellar input ; Cat ; Frog ; Golgi cell inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Field and unitary potentials evoked in the vestibulo-cerebellum of frog and cat following vestibular nerve stimulation were recorded with microelectrodes and correlated with their site of origin in the various layers of the cerebellar cortex. 2. In the frog, primary vestibular fibers project both as mossy and as climbing fibers onto the cerebellar auricular lobe. Secondary vestibulo-cerebellar fibers seem to end exclusively as mossy fibers in the auriculum. As a consequence of this dual projection, extra- and intracellular recordings from Purkinje cells in the auricular lobe show two kinds of responses to vestibular nerve stimulation: a) graded, repetitive firing mediated through mossy fiber-granule cell-parallel fiber pathways, and b) all-or-none burst responses caused by monosynaptic impingement of vestibular climbing fibers on Purkinje cells. 3. The field and unitary potentials evoked in the cat nodulus, flocculus and uvula following vestibular nerve stimulation are shown to be generated by mossy fibers exclusively. Considerable convergence of the two labyrinthine mossy fiber inputs to a given cerebellar area was found. 4. Interaction of contralateral and ipsilateral mossy fiber input at the level of the flocculus suggests that Golgi cell inhibition might operate not only as a simple inhibitory feedback loop, but also as a complex gating operator at the granule layer. 5. No short latency climbing fiber activation of Purkinje cells was observed following VIIIth nerve stimulation. Stimulation of the contralateral inferior olive evoked short latency climbing fiber EPSPs in Purkinje cells of the vestibulo-cerebellum. Suggestions are made as to the possible role of mossy and climbing fiber inputs to this area of the cerebellum.
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    URL: http://dx.doi.org/10.1007/BF00235450
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  • 22
    Electronic Resource
    Electronic Resource
    Pyramidal control of fusimotor neurons supplying extensor muscles in the cat's forelimb (1969)
    Springer
    Experimental brain research 9 (1969), S. 96-115 
    Details
    ISSN: 1432-1106
    Keywords: Pyramidal tract ; Fusimotor Neurons ; Forelimb ; Extensor ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of cortical stimulation upon dynamic and static sensitivities of the sensory endings in muscle spindles have been analyzed. 63 single afferent fibers from the muscle spindles of the forelimb extensors: M. flexor carpi radialis, M. flexor digitorum communis and M. palmaris longus were isolated in dorsal root filaments in 20 adult cats under chloralose-urethane anesthesia. They were identified by their response to stimulation of the median nerve. 1. Surface anodal repetitive stimulation of the anterior sigmoid gyrus was found to produce an enhancement of static response of single Group II fibers. Effective area was localized in a restricted region which corresponded to the forelimb motor area. The effect was obtained without any concomitant muscle contraction. Similarly, the stimulation increased the resting discharges of the Group Ia fibers from the same muscles. 2. Stimulation of the same area in the cerebral cortex was also found to increase the dynamic sensitivities of primary sensory endings. The increase was revealed by an enhancement of initial burst discharge during relaxation period of a twitch contraction caused by median nerve stimulation. 3. These results indicate that stimulation of the forelimb motor area has a facilitatory effect on both the static and dynamic fusimotor neurons innervating the muscle spindles of the test muscles. 4. The effects were reproduced in pyramidal tract preparations in which the brainstem was cut either at the level of the midbrain except for the cerebral peduncle or at the level of caudal medulla oblongata sparing the pyramid. 5. The threshold for the fusimotor effects was less than 1.3–1.5 times threshold of the pyramidal tract discharge, when the best spot for eliciting the fusimotor response was chosen. These results indicate that the effects of cortical stimulation are mainly mediated by the fast conducting pyramidal tract fibers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238324
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  • 23
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    Electronic Resource
    Die asynchrone und lokal umschriebene Reizwirkung von Mittelfrequenz-Dauerströmen im Hypothalamus der Katze (1969)
    Springer
    Experimental brain research 9 (1969), S. 164-182 
    Details
    ISSN: 1432-1106
    Keywords: Emotional behaviour ; Hypothalamus ; Electricalstimulation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. In order to compare the selective value of repetitive cathodal pulses of 8 c.p.s. and of continuous sine-wave alternating currents of 5000 c.p.s. (middle frequency current) when applied to brain tissue, explorations were made in the region of the hypothalamus that had yielded defence and/or flight reactions in earlier experiments. The region was explored by stimulating each point in turn with both current forms. At the same time measurement was made of the impedance of the brain tissue, and the effects produced by altering the time of rise of the middle frequency current on threshold of responses were also studied. The experiments were carried out on unanaesthetized, freely moving cats. 2. Both stimulation types produced affective (“emotional”) responses. The patterns elicited by low frequency cathodal pulse stimulation were often associated with stimulus-bound phasic muscle activity, i.e., flapping of ears, and twitching of whiskers, or, rotation of the head. Such extraneous motor effects were rarely obtained when continuous middle frequency currents were applied, and were tonic in character when present. 3. Mapping of reactive points revealed that the area producing defence or flight following middle frequency stimulation is smaller in size than the field delimited by means of repetitive cathodal pulse stimulation. These results strongly suggest that spread of current can be reduced by using middle frequency current stimulation. This apparently local (and hence highly selective) action is paralleled by a lower impedance of the brain tissue to the rapidly changing polarity of this current. 4. The hissing (and/or growling) associated with the defence pattern showed adaptation to suddenly rising middle frequency currents of 30 secs duration. An increase in threshold of hissing occurred when the time of rise of the current was prolonged. Flight, in contrast, was obtained at the same critical intensity regardless of the time of rise of current. 5. The nature of the stimulatory action of middle frequency current (examined in the peripheral nerve by Wyss) and the advantages presented by this new method of brain stimulation are briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238329
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  • 24
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    Electronic Resource
    Defence, attack, and flight elicited by electrical stimulation of the hypothalamus of the cat (1969)
    Springer
    Experimental brain research 8 (1969), S. 113-129 
    Details
    ISSN: 1432-1106
    Keywords: Emotional behaviour ; Hypothalamus ; Electrical stimulation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Affective behaviour patterns produced by electrical stimulation of the hypothalamus were studied in unanaesthetized, freely-moving cats. Bipolar stimulation with coaxial electrodes and small cathode was used to elicit defence, attack or flight. The development of these responses was studied by varying stimulation strength. In some experiments a stuffed animal was introduced in order to study the reactions of the cat to changes in the environment during stimulation. 2. The following responses were evoked at threshold intensity: (i) growling reaction; (ii) hissing reaction; (iii) two types of flight — type a preceded by hastily looking to and fro as if in search of an exit, type b preceded by inspection of surroundings, in most cases associated with sniffing. 3. Increasing stimulation 1.5 times threshold often yielded combined patterns. At points yielding the growling reaction a defence response in which growls alternated with hisses was obtained. The points yielding flight type a sometimes yielded hissing followed by flight. Increasing stimulation at hissing points yielded either a defence reaction or the combined effect hissing-flight. 4. The growling reactions were obtained from the tuber region. The hissing responses were obtained from points above the tuber. The flight reactions, type a, were produced from the intermediate zone extending from the level of the preoptic area to the mamillary bodies and type b from the caudo-lateral hypothalamus. 5. The reactions of the cats to a dummy during stimulation varied depending on the type of response which had been evoked in the absence of the dummy. The defence reaction was converted into threatening and striking of the dummy, the combined effects into threatening, striking or biting, culminating in sudden flight. The dummy was ignored during stimulation of points yielding flight type a, but examined by sniffing during stimulation of points yielding flight type b.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234534
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  • 25
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    Electronic Resource
    Interaction of defence and flight reactions produced by simultaneous stimulation at two points in the hypothalamus of the cat (1969)
    Springer
    Experimental brain research 8 (1969), S. 130-149 
    Details
    ISSN: 1432-1106
    Keywords: Emotional Behaviour ; Hypothalamus ; Electrical stimulation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The results presented in the present paper are an extension of preceding work devoted to exploration of the hypothalamic defence and flight fields using coaxial electrodes with small cathode. In 33 cats simultaneous stimulation was applied to two points which upon single stimulation had yielded defence, flight, or defence and flight respectively. Results were compared with those produced at either point alone. In 2 cats combined stimulation of a defence and a flight point was carried out with a stuffed cat present. 2. The latencies and rates of the vocal effects associated with defence (growling and hissing), and the latencies of flight (jump from the table) were measured. 3. Simultaneous stimulation of two points which had yielded defence, or of two points which had yielded flight resulted in facilitation (spatial summation) of the effects evoked: a more complete defence response associated with decrease of the latencies and increase in the rates of the vocal effects; decrease of flight latencies and increase of flight impetuosity. 4. Simultaneous stimulation of a defence point which had yielded growling at lower threshold than hissing, and of a point which had yielded flight resulted in facilitation of hissing. Growling and flight were often suppressed; when they occurred, latencies were lengthened and growling rates were increased somewhat. 5. Stimulation of a defence point with a dummy present produces striking (fending off). Simultaneous stimulation of a flight point resulted in facilitation of both hissing and striking. 6. It is concluded that the complex patterns obtained when defence is combined with flight are the result of facilitatory and inhibitory interaction between the elements of the individual patterns.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234535
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  • 26
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    Electronic Resource
    Eine faktorenanalyse von schwellen subcorticaler reizantworten (1969)
    Springer
    Experimental brain research 8 (1969), S. 79-96 
    Details
    ISSN: 1432-1106
    Keywords: Evoked potential thresholds ; Factor analysis ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zur Beschreibung von Korrelationen zwischen zahlreichen elektrophysiologischen Daten aus verschiedenen Hirngebieten wurde eine Faktorenanalyse nach der Hauptachsenmethode gerechnet. Ausgangsmaterial dieser Analyse waren Schwellen subcortical ausgelöster und abgeleiteter Antwortpotentiale auf Einzelreize. Das resultierende Faktorenmuster ermöglicht ein quantitatives Konzept der Schwellendetermination subcorticaler Reizantworten und zugleich ein Modell von Funktionsbeziehungen zwischen einigen Hirnstrukturen. Die Reizungen und Ableitungen erfolgten bei 35 encéphale isolé-Katzen mit Hilfe bipolarer Elektroden in folgenden Arealen: Amygdala, Hippocampus, Septum, N. dorsomedialis Thalami, Hypothalamus posterior und Formatio reticularis mesencephali. Es wurden 435 Korrelationskoeffizienten zwischen den Schwellen von 30 subcorticalen Verbindungen gebildet und zum Zwecke einer Datenreduktion durch eine Matrix von 5 Faktoren reproduziert. 1. Jeder Faktor repräsentierte hohe Schwellenkorrelationen zwischen den efferenten Projektionen jeweils eines Kerngebietes. Demnach nimmt im allgemeinen die Aktivität des Reizortes den größten Einfluß auf die Schwelle eines Antwortpotentials. Diese Hypothese ist durch pharmakologische Untersuchungen belegt worden [27] 2. Kovariationen von Reizantworten mit identischen Ableiteorten ergaben sich ausnahmslos, wenn die Latenzzeiten mehr als 11 msec betrugen. 3. Zusätzlich zeigte die Faktorenmatrix Schwellenkorrelationen zwischen: a) den hypothalamischen Efferenzen und mehreren hippokampalen Afferenzen langer Latenz (positive Korrelationen) b) retikulo-limbischen Verbindungen und „primären” Efferenzen von Amygdala und Hippocampus (positive Korrelationen) c) Antwortpotentialen, die durch Reizung der Formatio reticularis, und solchen, die durch Reizung des N. Amygdalae ausgelöst waren (negative Korrelationen) d) den Efferenzen des N. dorsomedialis Thalami und limbischen Projektionen langer Latenz zur mesencephalen Formatio reticularis (positive Korrelationen) Die Interpretation dieser Zusammenhänge bestätigt und erweitert einige bekannte Modelle von Beziehungen zwischen subcorticalen Kerngebieten. Abschließend wird mit Rücksicht auf die Linearität der mathematischen Methode die Anwendbarkeit der Faktorenanalyse auf Schwellen von Reizantworten diskutiert.
    Notes: Summary In 35 cats (encéphale isolé) evoked responses were elicited and recorded with bipolar electrodes from the amygdala, hippocampus, septum, dorsomedial thalamic nucleus, posterior hypothalamus, and mesencephalic reticular formation. Correlations between the thresholds of responses in different areas following stimulation of other areas were described by a factor analysis according to the principal axis method. 435 coefficients of correlation were calculated and reproduced by a matrix of 5 factors for the purpose of data reduction. Each factor represented high threshold correlations between the efferent projections of one region, which suggests that the activity of the stimulated site exerts a major influence on the evoked potential threshold. This is supported by pharmacological studies [27, 49]. Covariations of responses recorded in the same nucleus were always found, if the latencies exceeded 11 msec. The factor matrix indicated threshold correlations between: the efferent projections of the hypothalamus and several long latency afferent projections to the hippocampus (positive correlations); reticulo-limbic connections and “primary” efferent connections of the amygdala and hippocampus (positive correlations); evoked potentials following reticular and amygdaloid stimulation (negative correlations); the efferent projections of the dorsomedial thalamic nucleus and long latency limbic projections to the mesencephalic reticular formation (positive correlations). The interpretation of these relationships confirms and extends some well known models of relations between subcortical regions. The applicability of factor analysis to evoked potential thresholds is discussed with regard to the linearity of the mathematical method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234927
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  • 27
    Electronic Resource
    Electronic Resource
    Bildung von markscheidenähnlichen Spiralstrukturen durch lamelläre Astrocytenausläufer innerhalb subpialer und perivasculärer Gliosen des Säugetiergehirns (1969)
    Springer
    Acta neuropathologica 12 (1969), S. 98-102 
    Details
    ISSN: 1432-0533
    Keywords: Marginal Siderosis ; Electron Microscopy ; Myelin-Sheath-Like Structures ; Plaques Fibromyéliniques ; Gliosis, Perivascular, Subpial
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei Kaninchen mit einer experimentell erzeugten Randzonensiderose des Zentralnervensystems konnten elektronenmikroskopisch in der Großhirnrinde eigentümliche Spiralstrukturen beobachtet werden. Diese Spiralen fanden sich vornehmlich im Bereich von subpialen und perivasculären Gliosen vor. Sie bestanden aus äußerst dünnen lamellären Astrocytenausläufern, welche um andere astrocytäre Zellfortsätze oder um Dendriten aufgewickelt waren. Die spiralisierten Astrocytenausläufer wiesen in ihrem Inneren feine Filamente mit einer ziemlich regelmäßigen Anordnung auf. In radiärer Richtung ließen die astrocytären Lamellenspiralen eine periodische Schichtung erkennen, welche etwas an die von echten Markscheiden erinnerte. Es wird in Betracht gezogen, daß sie das submikroskopische Äquivalent der sog. Plaques fibromyéliniques darstellen.
    Notes: Summary Peculiar spiral structures could be observed by electron microscopy in the cerebral cortex of rabbits with an experimentally produced marginal siderosis of the central nervous system. These spirals were found predominantly within areas of subpial and perivascular gliosis. They consisted of extremely thin lamellar astrocyte extensions winding around other astroglial processes or dendrites. The spirally coiled astrocyte extensions exhibited within their interior fine filaments having a rather regular arrangement. In the radial direction, the astrocytic lamellae spirals showed a periodic stratification somewhat resembling that of true myelin-sheaths. They were considered to represent the submicroscopic equivalent of the socalled plaques fibromyéliniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685315
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  • 28
    Electronic Resource
    Electronic Resource
    Structural changes of the central nervous system in swayback (enzootic Ataxia) of lambs (1969)
    Springer
    Acta neuropathologica 12 (1969), S. 307-313 
    Details
    ISSN: 1432-0533
    Keywords: Swayback of Lambs ; Electron Microscopy ; Corpus Callosum ; Myelogenesis ; Axonal Changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Elektronenmikroskopische Untersuchung des Corpus callosum normaler Lämmer und von solchen mit „Swayback” (enzootische Ataxia) ergab den morphologischen Nachweis normaler Myelinentwicklung in beiden Tiergruppen. Von zwei Zellfortsätzen umgebene Axone wurden häufig beobachtet. Reaktive Veränderungen wurden in Axonen der „Swayback”-Lämmer gefunden. Die Bedeutung dieser Befunde wird besprochen.
    Notes: Summary An electron microscopic study of the corpus callosum of normal and swayback lambs has revealed morphological evidence of normal myelinogenesis in both groups of animals. Axons wrapped by two cell processes were frequently encountered. Reactive changes were found in axons in the swayback lambs. The significance of these findings is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00809127
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  • 29
    Electronic Resource
    Electronic Resource
    Intranucleäre stabförmige Gebilde bei einem Oligodendrogliom (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 289-293 
    Details
    ISSN: 1432-0533
    Keywords: Oligodendroglioma ; Nuclear Inclusions ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird die Ultrastruktur von intranucleären stabförmigen Gebilden bei einem Oligodendrogliom beschrieben.
    Notes: Summary Ultrastructure of intranuclear rodlets in an oligodendroglioma is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690649
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  • 30
    Electronic Resource
    Electronic Resource
    Electron microscopic studies on the cerebral lesions of rats in experimental carbon monoxide poisoning (1969)
    Springer
    Acta neuropathologica 14 (1969), S. 118-125 
    Details
    ISSN: 1432-0533
    Keywords: Carbon Monoxide Poisoning ; Electron Microscopy ; Myelin Disintegration ; Cerebral Anoxia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Nach experimenteller CO-Vergiftung fanden sich schwerere und ausgedehntere Läsionen in der weißen als in der grauen Hirnsubstanz. Zwischen akuter und chronischer CO-Vergiftung ergaben sich keine wesentlichen qualitativen Unterschiede der Hirnveränderungen. Die Läsionen nach chronischer Intoxikation waren jedoch schwerer als nach akuter Vergiftung. Die Nervenzellen zeigten leicht dilatiertes oder fragmentiertes EPR und Golgi-Komplexe, doch boten die Mitochondrien meist keine pathologischen Veränderungen. Bei chronischen Fällen fand sich gelegentlich eine deutliche Schwellung des EPR von Oligodendrogliazellen. Die Capillaren blieben intakt und die perivasalen Astrogliaendfüßchen waren nicht geschwollen. Im Mark kam es zu teilweisem Ausfall der normalen Markscheidenbestandteile. Die Marklamellen zeigten mäßige Exfoliation sowie eine Umwandlung in homogene oder strukturlose Substanz. Bemarkte Axone waren teilweise kontrahiert und zeigten auf Querschnitten unregelmäßige Form. Gelegentlich fand sich eine Vergrößerung der axonalen Mitochondrien und Zerstörung ihrer inneren Parallelstrukturen. Als Hauptfaktoren in der Pathogenese der Hirnveränderungen nach experimenteller CO_Vergiftung werden zerebrale Anoxie infolge CO-Hämoglobinbildung, cytotoxische Wirkung von CO auf das Hirngewebe und eine Störung der Blutzirkulation angenommen.
    Notes: Summary In experimental carbon monoxide poisoning, more marked and widespread pathological changes in the brain were seen in the white matter as compared with the gray matter. No essential difference, in the appearance of cerebral alterations, was detected between acute and chronic carbon monoxide poisoning. It was confirmed that the changes resulting from chronic poisoning showed a higher degree of severity as compared with those resulting from acute poisoning. Nerve cells with slightly dilated or fragmented endoplasmic reticulum and Golgi complex in the gray matter were found infrequently. However, most mitochondria did not show any kind of abnormality in such cells. A remarkable dilatation of the endoplasmic reticulum of oligodendrocytes was sometimes seen in chronic cases. Capillaries remained intact and astrocytic perivascular foot-plates were not swollen. In the white matter, the normal constituents of the myelin sheath were partially lost and the myelin lamellae showed moderate exfoliation, or a change into homogenous or structureless substance. Myelinated axons were partially contracted and showed an irregularity in shape in transverse sections. Enlargement of occasional axonal mitochondria and the destruction of their internal parallel structures were observed. Cerebral anoxia caused by carboxyhaemoglobin, together with the cytotoxic action of carbon monoxide on the brain tissue and the disturbance of blood circulation in the brain are suggested as the chief factors in the pathogenesis of the cerebral alterations induced by experimental carbon monoxide poisoning.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00686348
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  • 31
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    Electronic Resource
    Electron microscopic alterations in the vicinity of epileptogenic cobalt-gelatine necrosis in the cerebral cortex of the rat (1969)
    Springer
    Acta neuropathologica 14 (1969), S. 201-214 
    Details
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Epilepsy, Experimental ; Focus ; Cobalt Gelatine ; Plasmatic Infiltration ; Brain Edema
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 25 erwachsenen Ratten wurde ein epileptogener Kobaltgelatineherd in einer Standardregion der Hirnrinde erzeugt. Die Tiere wurden am 1., 3., 5., 8., 14. 21. und 28. Tag nach der Operation getötet. Das Gebiet des epileptogenen Herdes wurde elektronenmikroskopisch untersucht. Die frühesten Veränderungen bestanden in ödem. Später traten Veränderungen der Astrocytenfortsätze auf, die sich an die Basalmembranen der Capillaren anlegten; die Intercellularräume erweiterten sich, füllten sich mit elektronenoptisch dichten Massen und entwickelten ein “plasmatisches Infiltrat”. Allmählich breitete sich dieses Exsudat weiter um die Capillaren aus; es trat an Orten auf, wo die Astrocytenfortsätze und die Dendriten schwer geschädigt waren und erfüllte die weiteren Intercellularräume des Neuropils. Die Nervenzellen zeigten eine auffallende Widerstandsfähigkeit gegenüber diesem pathologischen Prozeß. Manchmal waren sie umschlossen von Exsudatmassen und zum Teil oder ganz der zarten neuralen und Astrocytenfortsätze beraubt, von denen sie normalerweise umgeben sind. Unsere Befunde werden als das ultrastrukturelle Korrelat der Schols'schen “plasmatischen Infiltration” interpretiert.
    Notes: Summary In 25 adult rats an epileptogenic cobalt-gelatine focus was produced in a standard region of the cerebral cortex. The animals were killed successively on the 1st, 3rd, 5th, 8th, 14th, 21st and 28th day after operation and the region of the epileptogenic focus was examined electron microscopically. The earliest changes were those of oedema. Later there occurred disturbances of the astrocytic processes which cling to the basement membranes of the capillaries; the intercellular spaces widened and filled with rather E. M. dense masses and a “plasmatic infiltrate” developed. Gradually this exudative substance spread even further from the capillaries. It appeared in places where the astrocytic processes were severely demaged and the dendrites were partly dissipated and it filled out the wide intercellular spaces of the neuropil. The nerve cells showed a striking resistance toward this pathological process. Sometimes they floated in the exudative masses but were partly or totally deprived of the fine neural and astrocytic processes which normally surround them. Our findings are interpreted as the ultrastructural correlate of Scholz's “plasmatic infiltration”.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685300
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  • 32
    Electronic Resource
    Electronic Resource
    Electron microscopic study of metachromatic leucodystrophy (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 149-156 
    Details
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Leucodystrophy, Metachromatic ; Enzyme Histochemistry, Electronmicroscopical ; Lysosomes ; Neurochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Dans la leucodystrophie métachromatique, les lipides anormaux s'accumulent dans les lysosomes des cellules gliales et des phagocytes. Les inclusions lipidiques les moins organisées sont les plus riches en phosphatases acides. Celles dont l'ultrastructure est prismatique ont une activité enzymatique très faible et semblent plus proches de corps résiduels que de lysosomes actifs. Il semble que l'absence d'arylsulfatase lysosomiale induise la persistance des sulfatides accumulés dans les lysosomes alors que les autres lipides provenant de la dégénérescence myélinique, seraient normalement catabolisés. Un remaniement progressif de l'ultrastructure du contenu des lysosomes en est la conséquence.
    Notes: Summary In metachromatic leucodystrophy abnormal lipids are stored within the lysosomes of the glial cells and phagocytes. The lipid inclusions which are the less structured are the richest in acid phosphatases. Those of which the ultrastructure is prismatic show a very low enzymatic activity and are more similar to residual bodies than to active lysosomes. It appears that the lack in lysosomal arylsulfatase leads to an accumulation of the sulfatide moiety of the stored lipids while the other lipids originating from the myelin breakdown, would be normally catabolized. This leads to a progressive transformation of the ultrastructure of the lysosome contents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687027
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  • 33
    Electronic Resource
    Electronic Resource
    Electron microscopic observations in mice infected with Japanese encephalitis (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 169-181 
    Details
    ISSN: 1432-0533
    Keywords: Japanese Encephalitis ; Experimental ; Electron Microscopy ; Virus Particles in Neurons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Groß- und Kleinhirnrinde, Plexus chorioideus und Rückenmark von Mäusen wurden nach intracerebraler Inoculation einer Hirnemulsion mit Virus der Encephalitis japonica (JEV) elektronenoptisch untersucht, um den Ort der JEV-Replikation zu bostimmen. 72 Std nach der Inoculation bei Beginn der encephalitischen Symptome enthielten 70 bis 80% aller Rindenneurone und Vorderhornzellen viele sphärische Partikel, die meist im zarten endoplasmatischen Reticulum (EPR) und vereinzelt im granulären EPR lokalisiert waren. Die Einzelpartikel zeigten eine gleichförmige Substruktur aus einem elektronendichten zentralen Hof von 25–30 mμ Durchmesser, einer äußeren, weniger elektronendichten Zone und einer äußersten Grenzmembran von 40 mμ Durchmesser. 96 Std nach der Inoculation zeigte das Cytoplasma der Rinden- und Vorderhornneurone sehr viele Vacuolen und Vesiceln. Partikel wurden weit verstreut in den Vacuolen und Vesiceln sowie erstmals im ERP der Sternzellen und Purkinjezellen angetroffen, allerdings in geringerer Zahl. Keine derartigen Partikel wurden in Kontrolltieren und normalen Mäusegruppen angetroffen. Sogenannte eosinophile intranucleäre Einschlüsse in Epithelzellen des Plexus chorioideus zeigten keine derartigen Partikel im Kern oder in den cytoplasmatischen Bläschen. Nachdem keine als JEV identifizierbaren Partikel in Glia- und Endothelzellen nachzuweisen waren, wird angenommen, daß das JEV echt neurotrop ist und sich im EPR der Nervenzellen repliziert.
    Notes: Summary Cerebral and cerebellar cortices, choroid plexus and spinal cord of mice, inoculated intracerebrally with a brain emulsion containing Japanese encephalitis virus (JEV), were studied electronmicroscopically to determine the cell type and the site of JEV replication. 72 hours after inoculation, when the mice began to show encephalitic symptoms, 70 to 80% of all cortical neurons and anterior horn cells contained many spherical particles mostly located in the smooth endoplasmic reticulum and a few in the granular endoplasmic reticulum. The individual particles demonstrated an uniform substructure consisting of an electron dense central core of 25–30 mμ diameter, an outer less electron dense zone and an outermost limiting membrane of 40 mμ diameter. 96 hours after inoculation, the cytoplasm of cortical neurons and anterior horn cells was observed to contain very many vacuoles and vesicles. Particles were found widely scattered throughout the vacuoles and vesicles, and were observed for the first time in the endoplasmic reticulum of the stellate neurons and in Purkinje cells, though fewer. No such particles were observed in control and normal mouse groups. So-called eosinophic intranuclear inclusions of epithelial cells of choroid plexus failed to show any particles in their nuclei or cytoplasmic vesicles. Considering that no particulate matter, identifiable as JEV, was identified within any of the glial cells or endothelium in this examination, it was concluded that JEV was really neurotropic and replicates in the endoplasmic reticulum of the neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687029
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  • 34
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    Electronic Resource
    Changes at the nodes of ranvier during wallerian degeneration: an electron microscope study (1969)
    Springer
    Acta neuropathologica 14 (1969), S. 237-249 
    Details
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Wallerian Degeneration ; Nodal Changes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über ultrastrukturelle Veränderungen in den Ranvierschen Knoten des N.suralis der Ratte im Laufe der Wallerschen Degeneration berichtet. Die Untersuchungen erfolgten 12 und 120 Std nach einer örtlichen Quetschungsverletzung. Die ersten bemerkbaren Veränderungen finden sich im Axon. Nodale und paranodale Anhäufungen von Mitochondrien, multivesikulären und lamellären Körpern, wie auch kleinen blasen- und röhrenartigen Bildungen sind teilweise in den Knoten sichtbar und am deutlichsten nach 24–36 Std erkennbar. Gleichzeitig erfolgt eine Aufsplitterung der Neurofilamente und Neurotubuli, die ihre Liniengestaltung verlieren und sich zusammenballen. Die Zone der erhöhten Dichte gerade unterhalb des nodalen Axolemmas bleibt erhalten. Veränderungen im Myelin beginnen etwas später und bestehen in einem vesikulären Verfall der Endomyelinlamellen und einer Trennung der Endomyelinschlaufen vom Axolemma durch Schwannzellenfortsätze. Dieser Vorgang schien mit einem Zurückziehen des Myelins vom Knoten im Zusammenhang zu stehen. Schwannzellenfortsätze erstrecken sich auch so weit, daß sie das nodale Axon bedecken, wobei sie die nodalen Schwannzellenfortsätze vom Axolemma trennen. Das Endstadium ist die Unterbrechung des nodalen Axons und die Verschmelzung der Myelinenden als Teil der Ovoidbildung.
    Notes: Summary Observations are reported on the ultrastructural alterations at the nodes of Ranvier in the rat sural nerve during the course of Wallerian degeneration. These were examined between 12 and 120 hours after a localized crush injury. The earliest detectable changes are in the axon. Nodal and paranodal accumulations of mitochondria, multivesicular bodies, lamellar bodies and small vesicular and tubular profiles are seen at a proportion of the nodes and are most evident at 24–36 hours. Concomitantly with this, the neurofilaments and neurotubulus fragment, lose their alignment and clump together. The zone of increased density just beneath the nodal axolemma is preserved. Changes in the myelin begin slightly later and consist of vesicular breakdown of the terminal myelin lamellae, and separation of the terminal myelin loops from the axolemma by Schwann cell processes. The latter event appeared to be associated with retraction of the myelin from the node. Schwann cell processes also extend to cover the nodal axon, separating the Schwann cell nodal processes from the axolemma. The final stage is the interruption of the nodal axon and the fusion of the ends of the myelin as part of ovoid formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685303
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  • 35
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    Electronic Resource
    Electron histochemical demonstration of gangliosides in normal and Tay-Sachs brain tissue (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 157-168 
    Details
    ISSN: 1432-0533
    Keywords: Gangliosides ; Tay-Sachs Disease ; Brain Subcellular Localization ; Hale Stain ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Reaktion von kolloidalem Eisen mit Sialomucinen (Hale stain) wurde zur elektronenmikroskopischen Darstellung der neuraminsäurehaltigen Ganglioside in den subcellulären Fraktionen des Gehirns angewandt. Zunächst wurde mit Hilfe tritiummarkierter Ganglioside überprüft, ob bei der Gewinnung subzellulärer Fraktionen Ganglioside nicht unspezifisch subcellulär adsorbiert werden. Eine nennenswerte Adsorption konnte ausgeschlossen werden. Das Verfahren wurde zuerst auf die aus Meerschweinchengehirnen isolierten Fraktionen angewandt. Da Nervenendigungen, Mitochondrien und Synapsenbläschen Hale-positiv reagierten, dienten Enzyminkubationen mit Neuraminidase und Hyaluronidase zur Differenzierung von anderen Hale-positiven sauren Substanzen. Schließlich wurde die Methode auf die cytoplasmatischen multilamellären Körperchen (MCB) übertragen, die aus Gehirnen an Tay-Sachs'scher Krankheit Verstorbener isoliert wurden. Aus den Versuchen konnte abgeleitet werden, a) daß die Hale-Färbung auch Ganglioside anfärbt, b) daß Ganglioside auf der Oberfläche der Membran von den multilamellären Körperchen und mit hoher Wahrscheinlichkeit auch auf der Membran der Nervenendigungen lokalisiert sind, c) daß die Synapsenbläschen eine positive Reaktion ergeben, die jedoch nicht mit Sicherheit auf vorhandene Ganglioside zurückgeführt werden kann, d) daß die äußere Mitochondrienmembran Hale-positive Substanzen enthält, deren Natur unbekannt ist.
    Notes: Summary The reaction of colloidal ferric oxide with sialomucins (Hale stain) was applied to sialic acid-containing gangliosides in subcellular fractions of the brain, in order to investigate their localization by electron microscopy. Prior to all experiments, a check was made, by means of tritium-labeled ganglioside, to confirm that the ganglioside content in the subcellular particles was not the result of an unspecific adsorption during the isolating procedure. No considerable unspecific adsorption could be registered. Hale stain was first applied to subcellular fractions obtained from guinea-pig brains. Since nerve-endings, mitochondria and synaptic vesicles gave a positive staining reaction, incubations with neuraminidase and hyaluronidase were carried out in order to achieve a differentiation. Finally, the method was applied to the membranous cytoplasmic bodies (MCB) which were isolated from the brain of a patient with Tay-Sachs disease. It was concluded that: a) Hale stain stains gangliosides also, b) gangliosides are localized in the membrane of membranous cytoplasmic bodies and also very probably in the membrane of nerve-endings, c) synaptic vesicles give a Hale-positive reaction which cannot with certainty be attributed to gangliosides, d) the outer membrane of mitochondria contains Hale-positive substances, the nature of which is not known.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687028
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  • 36
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    Electronic Resource
    An electron microscopic study of meningiomas (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 301-323 
    Details
    ISSN: 1432-0533
    Keywords: Meningiomas ; Electron Microscopy ; Endotheliomatous, Fibromatous Type ; Light Cells ; Dark Cells ; Histogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 17 chirurgisch entfernte Meningiome vom endotheliomatösen und 5 vom fibromatösen Typ wurden elektronenmikroskopisch untersucht. Unterschiede im Entwicklungsgrad der cytoplasmatischen Fortsätze und der Beziehungen zwischen den Plasmamembranen der Tumorzellen wurden in den endotheliomatösen Meningeomen beobachtet. In 4 fibromatösen Tumoren sind die zelligen Areale von bindegewebigen Räumen umgeben. Auch wenn die meisten Tumorzellen helle Zellen sind und sich nicht wesentlich von den Tumorzellen der endotheliomatösen Meningiome unterscheiden, ist die histologische Anordnung der fibromatösen klar von derjenigen der endotheliomatösen Meningeome zu trennen. Ausschlaggebend dafür ist die starke Entwicklung des Bindegewebes. Die Dunkelzellen lassen sich in zwei Typen gliedern: Typ I wird in vier Tumoren mit stark ausgebildetem Bindegewebe angetroffen. Die Analyse der inneren Zellstruktur sowie das Vorliegen von Übergängen zwischen hellen und dunklen Zellen machen es wahrscheinlich, daß diese nur verschiedene Typen einer einzigen Ursprungszelle darstellen. Die Bedeutung dieser verschiedenen Erscheinungsformen der Meningiomzellen wird diskutiert. Die Ultrastruktur der Tumorzellen ähnelt derjenigen der normalen arachnoidalen Zellen. Rückschlüsse auf die blastodermale Herkunft der normalen und tumoralen meninigalen Zellen auf Grund ihrer ultrastrukturellen Merkmale erscheinen verfrüht.
    Notes: Summary Seventeen surgically removed meningiomas of the endotheliomatous and five of the fibromatous type were investigated with an electron microscope. Differences of the development of cytoplasmic processes and the relations between plasma membranes of blastomatous cells were observed in endotheliomatous meningiomas. In four of the fibromatous tumors the cell groups were surrounded by spaces of connective tissue. Although most of the tumor cells were light cells and are not essentially different from the tumor cells of the endotheliomatous meningiomas, the histological structure of fibromatous meningiomas is clearly distinguished from the endotheliomatous type, because of the greater amount of connective tissue. The dark cells may be divided into two types: the first was found in those four tumors, where the connective tissue is well developed, while the second one only occurred in one of the tumors. The analysis of the inner cell structure as well as the presence of interstages between dark and light cells makes it probable that dark and light cells are different types of one original cell. The cause of this different appearance of the menigioma cells is discussed. The fine structure of the tumor cells showed a great similarity with that of normal arachnoidal cells. Conclusions on the blastodermic origin of normal and blastomatous meningial cells on the basis of ultrastructural characteristics, however, seem to be premature.
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    Abnormal sarcolemmal nuclei encountered in several cases of dystrophia myotonica (1969)
    Springer
    Acta neuropathologica 12 (1969), S. 183-188 
    Details
    ISSN: 1432-0533
    Keywords: Dystrophia myotonica ; Electron Microscopy ; Sarcolemmal Nuclei ; Myofibrillar Material
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In fünf Fällen von Dystrophia myotonica zeigte die elektronenoptische Untersuchung von bioptisch entnommenem Material zentrale und subsarkolemmale Kerne, die komplexe vacuoläre Areale um myofibrilläres Material enthalten. Diese bisher nicht beobachtete Veränderung könnte durch Verlagerung von myofibrillärem Material in den Kern während seiner Wanderung in das Faserzentrum durch Invagination, aber nicht Durchbrechung der Kernmembran bedingt sein.
    Notes: Summary In five cases of dystrophia myotonica electron microscope preparations of muscle taken at biopsy showed both centrally placed and subsarcolemmal nuclei containing complex vacuolar areas enclosing myofibrillar material. It is suggested that this appearence, which has not been seen in any other condition, may be due to the forcing of myofibrillar material into the nucleus during its migration to the centre of the fibre invaginating but not breaching its membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00692505
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    Light and electron microscopic study of the muscles in hypokalemic periodic paralysis (1969)
    Springer
    Acta neuropathologica 12 (1969), S. 329-338 
    Details
    ISSN: 1432-0533
    Keywords: Hypokalemic Periodic Paralysis ; Electron Microscopy ; Myopathy ; Sarcoplasmic Reticulum ; Glycogen, Muscular
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Licht- und elektronenoptische Untersuchungen wurden an Muskelbiopsien von 4 Fällen hypokaliämischer periodischer Paralyse durchgeführt. Die frühesten Veränderungen betreffen nach Meinung der Verfasser das sarkoplasmatische Reticulum: Vacuolisierung des Längssystems und vermutlich Multiplikation des Quersystems. Es wird vermutet, daß die Vacuolenbildung die Folge einer Fusion der Vesikeln des Quersystems darstellt. Destruktion von Myofibrillen und Vergrößerung der, interfibrillären Räume treten erst in späteren Phasen des Krankheitsprozesses auf. Ausdehnung und Intensität dieser Veränderungen bedingen das typische histologische Bild myogener Läsionen bei Fällen m klinisch fixierten Symptomen der Myopathie.
    Notes: Summary Light and electron-microscopic studies were performed on the muscles taken from 4 cases with hypokalemic periodic paralysis. The authors conclude that the earliest changes concern the sarcoplasmic reticulum: vacuolisation of the longitudinal system and probably, multiplication of the transverse system. It is suggested, that vacuoles are formed as a result of fusion of the vesicles of the transverse system. Destruction of myofibrilles and enlargement of the interfibrillar spaces appear at a later period of the disease process. Extensive and intensive changes of that kind present a typical appearance of myogenic changes in histological study observed in the cases with clinically fixed symptomes of myopathy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00809129
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    Electronic Resource
    Ultrastructural and histochemical studies of cortical biopsies in subacute dementia (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 43-55 
    Details
    ISSN: 1432-0533
    Keywords: Subacute Dementia ; Jakob-Creutzfeldt Disease ; Brain Biopsy ; Histochemistry ; Electron Microscopy ; Basement Membrane ; Astroglia Dilatation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die elektronenoptische und histochemische Untersuchung von Biopsiematerial bei zwei Fällen subakuter Demenz ergab Neurone mit reichlich Lipofuscin-Depots sowie erhöhter saurer Phosphatase-Aktivität. Obwohl diese Veränderungen eine Nervenzellerkrankung anzeigen dürften, werden sie wegen ihrer Ähnlichkeit sowie wegen des Vorliegens anderer, spezifischerer Zellveränderungen als Sekundärphänomene gedeutet. Im ersten Fall wird als primäre Läsion eine Verdickung der Basalmembran der Gefäße, im zweiten Fall eine Astrogliaschwellung angenommen. Da diese Strukturen wichtige Transportfunktionen haben dürften, könnten diese Anomalien leicht die neuronale Versorgung stören und dadurch die neuronalen Läsionen verursachen. Die Bedeutung des Glykogens in diesen Strukturen wird diskutiert.
    Notes: Summary The electron microscopic and histochemical findings in biopsies of two cases of subacute dementia have revealed neurons containing numerous lipofuscin bodies and increased acid phosphatase. Although these changes are considered to indicate neuron disease, they are believed to represent a secondary process because of their similarity and because other more distinctive cell alterations are present. In the first case, the primary abnormality is believed to be thickening of the vascular basement membrane, while in the second case, astroglial dilatation is considered a primary change. Since these structures appear to have important transport functions, these abnormalities could easily impair the nutrient supply to neurons and, in this way, produce the neuronal alteration. The significance of glycogen in these tissues is discussed.
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    URL: http://dx.doi.org/10.1007/BF00686140
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    Electronic Resource
    Ultrastructural study of a nerve biopsy from a case of early infantile chronic neuropathy (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 131-142 
    Details
    ISSN: 1432-0533
    Keywords: Neuropathy, Chronical ; Hypertrophic Neuritis ; Schwann-Cell ; Onion Bulb ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die wesentlichen Veränderungen bei dem mitgeteilten Fall von chronischer frühinfantiler Neuropathie bestehen in einer Modifikation der Schwann-Zellen, die zur Bildung eines konzentrischen Netzwerkes von Lamellen führt. Dieses wird durch eine doppelkonturierte Hülle der Basalmembran um zahlreiche große bemarkte und unbemarkte Fasern gebildet. Die Anomalien der Markscheiden sowie die Häufigkeit von Desmosomen sind bemerkenswert. Diese Besonderheiten unterscheiden diesen Fall von anderen, bisher beschriebenen chronischen Neuropathien. Trotzdem erscheint es derzeit nicht möglich, eine Aussage über die Spezifität der ultrastrukturellen Befunde am untersuchten Nerven zu treffen.
    Notes: Summary The principal lesion in this case of chronic early infantile neuropathy is a modification of the Schwann cell resulting in the formation of a concentric network of lamellae formed by a double-layered sheet of basement membrane around numerous, large myelinated and unmyelinated fibers. The abnormalities in the myelin sheaths and the frequency of desmosomes are noteworthy. These peculiarities distinguish this case from other chronic neuropathies described up to now. Nevertheless, it is impossible to say at present whether the ultrastructural aspect of the nerve studied here is in any way specific.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00687025
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    Electronic Resource
    Granulomatous encephalitis in Whipple's disease (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 1-11 
    Details
    ISSN: 1432-0533
    Keywords: Whipple's Disease ; Granulomatous Encephalitis ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Von 21 Fällen von Whipplescher Krankheit in der Sammlung des Armed Forces Institute of Pathology zeigten 4 Fälle neurologische Symptome mit besonders ausgeprägten Hirnläsionen. Lichtmikroskopisch bestanden die Herde aus knötchenförmigen Anhäufungen von Makrophagen, deren Cytoplasma mit Hämatoxylin-Eosin eine charakteristische schwachblaue und nach Durchführung der Perjodsäure-Schiff-Reaktion eine stark rote Färbung zeigte. Elektronenmikroskopisch fanden sich in den Hirnläsionen Bacillen, die morphologisch den im Darm beschriebenen glichen und die auch dieselben Degenerationserscheinungen aufwiesen. Die Perjodsäure-Schiff-Reaktion färbt Kapselmaterial und Zellwände,die auch nach Untergang der Bacillen noch nachweisbar sind. Diese Beobachtungen werden als weiterer Beweis für die infektiöse Ätiologie der Whippleschen Krankheit angeführt.
    Notes: Summary Among the 21 autopsied cases of Whipple's disease on file at the Armed Forces Institute of Pathology, 4 had neurological symptoms and prominent involvement of the central nervous system, By light microscopy the lesions were composed of nodular aggregates of macrophages having cytoplasm that stained a distinctive pale blue with hematoxylin-eosin and bright red with the periodic acid-Schiff technique. By electron microscopy the cerebral lesions revealed bacilli morphologically identical to and undergoing the same sequence of degenerative changes as those observed in the intestine. The periodic acid-Schiff reaction stains the walls and the capsular material that persists even after intact organisms disappear. These observations further support the infectious nature of Whipple's disease.
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    URL: http://dx.doi.org/10.1007/BF00686137
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    Electronic Resource
    The normal sural nerve in man (1969)
    Springer
    Acta neuropathologica 13 (1969), S. 197-216 
    Details
    ISSN: 1432-0533
    Keywords: Peripheral Nerves ; Axons ; Myelin Sheaths ; Schwann Cells ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine kombinierte licht- und elektronenmikroskopische Untersuchung am normalen N. suralis von 7 Menschen im Alter von 15–59 Jahren wurde vorgenommen. Qualitative und quantitative Beobachtungen an Schwann-Zellen und Fibroblasten, markhaltigen und marklosen Fasern wurden an isolierten Faszikeln durchgeführt. Schwannzellen überwiegen gegenüber Fibroblasten im Verhältnis von etwa 9:1. Die meisten Schwannzellen (etwa 80%) liegen an marklosen Fasern. Die Faktoren, welche die Dichte dieser Zellen pro Querschnittsareal beeinflußen, werden diskutiert. Einige ultrastrukturelle Befunde an bemarkten Fasern werden beschrieben und ihre Zahl pro mm2 sowie die Häufigkeitsverteilung ihrer Dicke wird angegeben. Eine indirekte Methode zur Bestimmung der mittleren Internodienlänge für jede der Markfasergrößenpopulationen an Querschnitten von Faszikeln normaler Nerven durch Bestimmung des Verhältnisses der markhaltigen Fasersegmente zu ihrer Kernzahl wird vorgeschlagen. Die Ultrastruktur der marklosen Nervenfaern wird beschrieben und die Identifizierung dieser Axone mit extremen Durchmessern diskutiert. Ihre Dichte und Größenfrequenzhistogramme sind die ersten, die am Menschen durch systematische elektronenoptische Untersuchungen veröffentlicht werden. Das mittlere Verhältnis von marklosen zu bemarkten Fasern ist etwa 3,7:1 und schwankt in den Faszikeln der Einzelindividuen.
    Notes: Summary A combined light and electron microscope study of the normal sural nerve in 7 people aged 15–59 years is reported. Qualitative and quantitative studies of the Schwann cells and fibroblasts, myelinated and unmyelinated fibres are made in isolated fascicles. Schwann cells predominate over fibroblasts in the ratio of about 9-1. Most Schwann cells, almost 80%, are attached to unmyelinated fibres. Factors influencing the densities of these cells per cross sectional area are discussed. Some ultrastructural features of the myelinated fibres are described and their numbers per sq.mm and frequency distribution of their sizes are produced. An indirect method is proposed for assessing the mean internodal length for earch of the myelinated fibre size populations in cross sections of fascicles of normal nerves by estimating the proportion of myelinated segments cut through their nucleus. The ultrastructure of unmyelinated fibres is described and the identification of axons of extreme diameter is discussed. Their densities and size frequency histograms are the first to be reported in man by systematic electron microscope studies. The average ratio of unmyelinated to myelinated fibre density is about 3.7:1 though it varies in the fascicles of the different individuals. The implications of axonal diameter in the presence of myelin are commented on.
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    URL: http://dx.doi.org/10.1007/BF00690642
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    Electronic Resource
    Familial spongy degeneration of the central nervous system (Van Bogaert-Bertrand disease) (1969)
    Springer
    Acta neuropathologica 12 (1969), S. 103-115 
    Details
    ISSN: 1432-0533
    Keywords: Spongy Degeneration of the CNS ; Van Bogaert-Bertrand-Disease ; Electron Microscopy ; Astrocytic Mitochondria ; Abnormal Cerebral Edema
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über licht- und elektronenoptische Untersuchungen an Muskel-und Hirnbiopsien eines Falles von spongiöser Degeneration des ZNS berichtet. Die in der grauen und weißen Hirnsubstanz enthaltenen Vacuolen entsprechen a) Spalten in den Markscheiden infolge Aufsplitterung an der intraperiodischen Linie und b) geschwollenen Astrocytenperikaryen und-fortsätzen. Ungewöhnliche Mitochondrien mit Gehalt an kristallinem Material fanden sich nur in Astrocyten. Die ultrastrukturellen Befunde entsprechen denen des Hirnödems. Es wird angenommen, daß die Astroglia eine primäre Rolle in der Flüssigkeitsansammlung spielt, während die Markscheidenschwellung als eine Sekundärläsion aufgefaßt wird. Die mögliche Bedeutung abnormer Astrocyten-Mitochondrien wird diskutiert.
    Notes: Summary Light and electron microscopy study of skeletal muscle and cerebral biopsies from a case of spongy degeneration of central nervous system is reported. The multiple vacuoles present in cerebral gray and white matter correspond to (a) clefts within myelin sheaths resulting from splitting at the intraperiod line and (b) swollen astrocytic perikarya and processes. Unusual mitochondria containing crystalline-like material were observed only in astrocytes. The ultrastructural findings are consistent with cerebral edema. It is suggested that the astrocytes play a primary role in the fluid accumulation while the myelin swelling is a secondary lesion. The possible role of the abnormal astrocytic mitochondria is discussed.
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    URL: http://dx.doi.org/10.1007/BF00692500
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    Electronic Resource
    Étude ultrastructurale de quatre cas de leuco-encéphalite sclérosante subaiguë (1969)
    Springer
    Acta neuropathologica 14 (1969), S. 1-13 
    Details
    ISSN: 1432-0533
    Keywords: Subacute Sclerosing Leucoencephalitis ; Electron Microscopy ; Tubular Inclusions ; Inclusion Bodies (Cristalline Rods, Fibrillar Bundles, Nuclear Bodies, Osmiophilic Particles)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les auteurs rapportent 4 observations caractéristiques de LESS: L'analyse ultra-structurale montre: 10 — des inclusions tubulaires intra-nucléaires neuronales ou gliales et intra-axonales de morphologie superposable à celle des nucléocapsides des myxo-virus, de la rougeole en particulier. 20 — des formations non spécifiques: corps nucléaires, faisceaux cristallins et fibrillaires traduisant un trouble métabolique nucléaire, particules osmiophiles liées à une hyperactivité cellulaire. Les inclusions tubulaires virales sont présentes quelque soit la durée de la maladie (3 mois à 5 ans) indiquant l'absence d'autostérilisation virale dans le S.N.C. La LESS apparaît liée au virus rougeoleux mais le mécanisme indirect immunitaire ou métabolique de cette action est inconnu.
    Notes: Summary Four cases of S.S.L.E are reported. The electron microscopy findings show: 1. Tubulary inclusion bodies: They appear in three cases out of four, either in neuronal and glial nucleus or in axis cylinders. Their morphological features are similar to the nucleocapsides of myxoviruses and particularly measles-virus. 2. Other different types of nonspecific inclusions: nuclear bodies, cristalline-like rods and fibrillar bundles which may be considered as the result of a nuclear metabolic disorder, osmiophilic particles which may be seen as the result of a cellular intracytoplasmic hyperactivity. The tubules are found whatever the duration of the disease (3 months up to 5 years) may be. This might indicate that there is no autosterilization of the virus in the C.N.S. during the course of S.S.L.E. According to the most recent papers, such a disease might be interpreted as an infection indirectly induced by measles-virus with an unknown immunologic or metabolic mechanism.
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    URL: http://dx.doi.org/10.1007/BF00687698
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    Electronic Resource
    Electron microscope study of the rat brain with experimental sodium azide intoxication (1969)
    Springer
    Acta neuropathologica 14 (1969), S. 185-193 
    Details
    ISSN: 1432-0533
    Keywords: Hypoxia ; Sodium Azide ; Electron Microscopy ; Ferritin ; Capillary Permeability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Experimentelle histotoxische Hypoxämie wurde in Ratten durch Natriumacid-Vergiftung erzeugt. Die mikroskopische Untersuchung der Hirne ergab keine Veränderung, aber bei der elektronenmikroskopischen Untersuchung fanden sich als Frühveränderungen in der Hirnrinde und im Subcortex eine Erweiterung der intercellulären Räume und eine Anschwellung der pericapillären Astrocytenfortsätze. Ferritinalbumin-Mischung, die als Indicator des Eiweißtransportes benutzt wurde, zeigte keine Vermehrung der Capillarpermeabilität. Es wird vermutet, daß Natriumacid den Wasserstoffwechsel beeinträchtigt, wobei es eine osmotische Ausgleichstörung im Gehirn erzeugt.
    Notes: Summary Histotoxic hypoxia was experimentally produced in the rat brain by sodium azide intoxication. In spite of the absence of light microscopic alterations, electron micrographs showed the early changes in the cerebral cortex and subcortex which consisted of widening of the intercellular space and swelling of the pericapillary astrocytic end-feet. However, ferritin-albumin mixture, used for the tracer of protein transport, did not show any increase in the capillary permeability. Sodium azide was considered to disturb the water metabolism, producing osmotic unbalance in the brain.
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    URL: http://dx.doi.org/10.1007/BF00685298
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  • 46
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    Electronic Resource
    An hallucinogenic amphetamine analog (DOM) in man (1969)
    Springer
    Psychopharmacology 14 (1969), S. 62-73 
    Details
    ISSN: 1432-2072
    Keywords: Amphetamine ; Hallucinogens ; Drug Addiction ; Psychopharmacology ; Phenylethylamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The amphetamine analog, 2,5-dimethoxy-4-methylamphetamine (DOM), was studied in 18 volunteer subjects given single doses ranging from 2 to 14 mg. The former was a threshold dose, with definite psychotomimetic effects being evident from doses over 5 mg. The clinical syndrome greatly resembled that of the LSD-mescaline-psilocybin series of drugs, including its time-course. Somewhat more sedation was produced by DOM than would have been expected from the others, despite concomitant evidence of peripheral sympathetic stimulation. Just as with the other drugs, DOM increased plasma free fatty acids, decreased phosphorus and creatinine clearance, decreased circulating eosinophils and had little effect on catecholamine excretion. Performance of psychometric tests was impaired. Chlorpromazine treatment concurrently was found to attenuate the reaction. Tolerance rapidly developed when the drug was used chronically by patients.
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    URL: http://dx.doi.org/10.1007/BF00401535
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  • 47
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    Electronic Resource
    Generalization by rats of alcohol and atropine stimulus characteristics to other drugs (1969)
    Springer
    Psychopharmacology 15 (1969), S. 196-206 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Animal Behavior ; Alcohol ; Atropine ; Discrimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two operant procedures were used for training albino rats to make differential responses on the basis of their drug or nondrug condition. In the Conflict procedure, every fifth lever press was rewarded by a food pellet in one condition (drug for half the animals, saline for the other half) and was punished by electric shock in the other condition. For 6 animals the drug condition was ethyl alcohol (1200 mg/kg of a 10% v/v solution in isotonic saline, injected i.p. 5 min before the start of the session); for 4 animals the drug condition was atropine sulfate (10 mg/kg in 1 ml/kg saline injected i.p. 30 min before the start of the session). In the Choice procedure, food reward was obtained by the first press on one of two levers at a variable time interval, averaging one minute, after the prior food reward. The rewarded lever depended on the animal's drug or saline condition (alcohol for 7 animals, atropine for 5 animals, administered as in the Conflict procedure); the same right-hand or left left-hand lever was rewarded in the drug condition for half the animals and in the saline condition for the other half. The response associated with 1200 mg/kg alcohol was generally elicited in tests with sufficiently high doses of pentobarbital sodium (10–20 mg/kg), chlordiazepoxide hydrochloride (10–15 mg/kg) and chloral hydrate (90–120 mg/kg, administered orally). Lower doses of these compounds, and of alcohol, were perceived as less similar to the alcohol and therefore more similar to the saline condition. Substantial doses of chlorpromazine hydrochloride (2 mg/kg) and d-amphetamine sulfate (1 mg/kg) also were perceived as similar to the saline condition. The response associated with a centrally acting anticholinergic (10 mg/kg atropine) was generally elicited in tests with several doses of scopolamine hydrobromide (0.06 to 1.0 mg/kg) and of atropine (2.5–5.0 mg/kg). The saline response was elicited by a lower dose of scopolamine (0.03 mg/kg) and by a peripherally-acting anticholinergic, atropine methyl bromide, at a dose (5 mg/kg) equimolar with 10 mg/kg atropine sulfate. The same results, including closely similar ED50 doses, were generally found with the Conflict and Choice procedures, despite the differences between them in the motivational basis for the differential drug and nondrug responses. The similarities and dissimilarities among these compounds in perceived stimulus characteristics also correspond closely with those reported by Overton (1966) with a locomotor shock-escape procedure in tests which were generally limited to a single high dose of each drug.
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    URL: http://dx.doi.org/10.1007/BF00411169
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    Electronic Resource
    Antagonism by antimuscarinic and ganglion-blocking drugs of some of the behavioural effects of nicotine (1969)
    Springer
    Psychopharmacology 15 (1969), S. 341-350 
    Details
    ISSN: 1432-2072
    Keywords: Nicotine ; Antimuscarinic Drugs ; Ganglion-Blocking Drugs ; Operant Conditioning ; Psychopharmacology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of nicotine on bar-pressing behaviour in the rat are blocked by mecamylamine. The depressant phase of the effect is blocked by atropine, supporting the conclusion that this depression is mediated by released acetylcholine. The quaternary compounds chlorisondamine and atropine methylnitrate also antagonise the behavioural effects of nicotine but the doses required for this are far in excess of those which are effective peripherally, suggesting that the sites of interaction are central.
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    URL: http://dx.doi.org/10.1007/BF00403709
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  • 49
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    Electronic Resource
    Nicotine injections as the conditioned stimulus in discrimination learning (1969)
    Springer
    Psychopharmacology 15 (1969), S. 351-360 
    Details
    ISSN: 1432-2072
    Keywords: Nicotine ; Conditioned Stimulus ; Discrimination Learning ; Psychopharmacology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats were trained to respond for water rewards on different bars in a Skinner box depending on whether they had previously been injected with nicotine or with saline. No other drug tested could consistently elicit responses on the “nicotine correct” bar. Pre-treatment with mecamylamine abolished the rats' ability to distinguish between nicotine and saline but pretreatment with chlorisondamine did not.
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    URL: http://dx.doi.org/10.1007/BF00403710
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  • 50
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    Electronic Resource
    Effects of LSD on the spontaneous and evoked activity of retinal and geniculate ganglion cells (1969)
    Springer
    Psychopharmacology 15 (1969), S. 382-391 
    Details
    ISSN: 1432-2072
    Keywords: LSD ; Retina ; LGN ; Single Unit Activity ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of LSD 25 (i. v. injection) on the spontaneous and evoked activity of the visual system was investigated in cats. 50 γ/kg did not change significantly the ERG and the visual cortical evoked potential. The spontaneous discharge rate of 14 out of 21 retinal ganglion cells showed an increase which reached its maximum within 20–30 min and which could still be present 1 hour following the injection. One third of the retinal units showed a slight depression of their spontaneous dischaRge rate with about the same time course. Single units of the LGN showed about the same behaviour. The response to light stimulation was slightly increased in some units and light induced inhibition was slightly shortened. The possible mechanism of the LSD-effect on retinal ganglion cell activity is discussed.
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    URL: http://dx.doi.org/10.1007/BF00403713
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    Alteration of the behavioral effects of amphetamine by agents which modify cholinergic function (1969)
    Springer
    Psychopharmacology 14 (1969), S. 142-149 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Amphetamine ; Cholinergics ; Drug Interactions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Amphetamine was administered to a group of rats trained on a nondiscriminated avoidance procedure. An intraperitoneal dose of 2.0 mg/kg caused about a 75% increase in response rate for the three-hour session. Doses of atropine, Tremorine, eserine, and 4-(1-naphthylvinyl)-pyridine (NVP), an inhibitor of the enzyme choline acetylase, which were ineffective in themselves, markedly affected the increase in rate observed after amphetamine. The quarternary amine of NVP was without effect on the amphetamine response. Those agents that decreased cholinergic function, either by blocking the effect of acetylcholine or by preventing its synthesis, augmented the stimulating effect of amphetamine. Cholinergic stimulants, on the other hand, significantly antagonized the behavioral effects of amphetamine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00403687
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    The effects of nicotine on punished behaviour (1969)
    Springer
    Psychopharmacology 14 (1969), S. 221-232 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Animal Behaviour ; Nicotine ; Punishment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of nicotine, amphetamine, chlordiazepoxide and caffeine were studied in rats trained on a VI 2 crf schedule of water reward with all rewards accompanied by electric shock. Responding, partially suppressed by the shock, was restored by chlordiazepoxide and further suppressed by amphetamine. Nicotine resembled amphetamine in its effects on most rats but occasionally increased responding. Caffeine also increased responding in some rats indicating that this property is not always confined to tranquillising drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00404220
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    Psychopharmacological activity of the active constituents of hashish and some related cannabinoids (1969)
    Springer
    Psychopharmacology 14 (1969), S. 200-210 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Hashish ; Cannabinoids ; Monkeys Amphetamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The psychopharmacological activity of Δ 1-tetrahydrocannabinol, (I); Δ 1(6)-tetrahydrocannabinol (4′ hexyl), (II); Δ 1(6)-tetrahydrocannabinol, (III); 1-ethoxyhexahydrocannabinol, (IV); 8-ethoxy-iso-hexahydrocannabinol, (V); Δ 1(6)-tetrahydrocannabinolic acid Me ester, Isomer I, (VI); Δ 1(6)-tetrahydrocannabinolic acid Me ester, Isomer II, (VII); cannabigerol, (VIII); Δ 1(6)-tetrahydrocannabinol (3′ hexyl), (IX); cannabichromene, (X); has been examined in a variety of animal species. 2. Compounds (I) and (III) caused severe motor disturbances and a stuporous state in dogs and ptosis, “tameness” and peculiar postural changes in monkeys. In the latter animal, compound (II) elicited similar effects. 3. Compounds (I) and (III) after intraperitoneal but not subcutaneous administration, suppressed the gerbil digging activity; reduced the rat conditioned avoidance response and induced a cataleptoid reaction in mice, rats and gerbils. In addition, compound (I) reduced the performance of mice on the rotating-rod. Both compounds, administered subcutaneously, induced a measurable ataxic gait in rats. 4. Amphetamine reversed the behavioural changes elicited by compounds (I) and (III) in monkeys, as well as the cataleptoid reaction in rats. 5. None of the other compounds provoked observable changes in any of the species studied. 6. It is suggested that Rhesus monkeys might serve as a suitable model for assessing the psychopharmacological activity of active cannabinoids.
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    URL: http://dx.doi.org/10.1007/BF00404218
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    Über die antiaggressive Wirkung von Lithium (1969)
    Springer
    Psychopharmacology 15 (1969), S. 245-254 
    Details
    ISSN: 1432-2072
    Keywords: Aggression ; Lithium ; Psychopharmacology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The influence of lithium on aggressive behavior was studied in Siamese fighting fish, mice and golden hamsters. The fish stopped fighting when exposed to concentrations of 10 to 30 meq/l LiCl in the surrounding water. Also in mice and hamsters which ingested LiCl with the drinking fluid lithium abolished intraspecific aggression. Measurements of plasma and brain lithium levels revealed astonishing individual differences in the concentrations which were necessary for the antiaggressive effect. In all species normal aggressive behavior reappeared after lithium treatment was discontinued.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00401678
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    Assessment of anti-reserpine and anti-apomorphine activities of some psychic energizers in pigeons (1969)
    Springer
    Psychopharmacology 15 (1969), S. 255-259 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Antidepressants ; Reserpine Emesis ; Apomorphine Pecking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Seven psychic energizers have been quantitatively evaluated for their antidepressant and tranquillizing activity using antagonism of reserpine induced emesis and apomorphine induced pecking in pigeons as test procedures for the two activities respectively. Pheniprazine and deanol possess anti-reserpine activity only whereas imipramine, desmethylimipramine, amitriptyline, opipramol and orphenadrine possess both anti-reserpine as well as anti-apomorphine activity. It is suggested that the two tests form a simple and reliable combination for evaluating potential antidepressants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00401679
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    A clinical trial of methysergide and lithium in mania (1969)
    Springer
    Psychopharmacology 15 (1969), S. 425-429 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Methysergide ; Mania ; Lithium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six manic patients were studied in an open sequential drug trial of placebo and the serotonin antagonist methysergide; lithium was then substituted double-blind. No dramatic change occurred in individual manic item scores or in mean daily mania ratings after 48 hours or seven days of methysergide, although several of the patients showed slight trends toward improvement. However, after a mean duration of 10.3 days of lithium treatment, all manic item scores improved dramatically and significantly, so that complete clinical remission was evident in all patients. In view of the discrepancy between these essentially negative findings and several recent positive reports on the efficacy of methysergide in the treatment of mania, the authors feel that the indolealkylamine hypothesis of affective disorders should be further investigated.
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    URL: http://dx.doi.org/10.1007/BF00403718
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    The effect of nicotine on the swimming speed of pre-trained rats through a water alley (1969)
    Springer
    Psychopharmacology 15 (1969), S. 19-27 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Animal Behavior ; Nicotine-Physical Performance ; Motivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In sessions of ten runs each, swimming time of rats through a 4 m long water alley was measured. Four doses of nicotine (0.05; 0.1; 0.2; 0.4 mg/kg given intraperitoneally 30 minutes before testing) were tested in sessions with a braking load on the tails of the animals either in all 10 runs of a session, or in every second run, or in none of the 10 runs. Regardless of the swimming condition, nicotine produced a considerable, and at doses of 0.1 mg/kg and over, significant decrease of performance in the first two runs. From the third to the 10th run, the changes caused by nicotine were smaller and differed depending on the swimming conditions. A dose of 0.1 mg nicotine/kg improved performance in the “without-load-sessions” and the “without-load-runs” of the alternating sessions, while both 0.1 and 0.2 mg/kg improved performance of the “with-load-runs” of the alternating sessions. Performance in the “without-load-sessions” and the “without-load-runs” was depressed by 0.4 mg/kg and that in the “with-load-sessions” by 0.2 and 0.4 mg/kg.
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    URL: http://dx.doi.org/10.1007/BF00410797
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    Alpha chloralose and nocturnal physiological patterns (1969)
    Springer
    Psychopharmacology 15 (1969), S. 28-38 
    Details
    ISSN: 1432-2072
    Keywords: Drugs ; Sleep ; Electroencephalography ; Psychophysiology ; Psychopharmacology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sleep physiological patterns were examined following a single oral dose (500 mg) of the hypnotic drug alpha chloralose. The drug increased SW sleep and decreased REM sleep without affecting total sleep time or the amount of stage 2. These changes were accompanied by a shift to slower frequencies and greater EEG synchrony, as well as a decrease in the number of spontaneous arousals in all stages of sleep, and throughout the night of medication. Except for a slight decrease in eye movement density, the drug had no systematic effects on phasic phenomena such as electrodermal or cardio-respiratory fluctuations, nor was there a systematic change in basal heart and breathing rates. On the night following medication a “rebound” increase in percent stage REM was associated with a sharp decrease in SW sleep, and increases in spontaneous arousals and waking time. Such findings suggest that sleep stages are controlled by homeostatic mechanisms whose function is to maintain equilibrium. A comparison of the effects of alpha chloralose with those of the barbiturate secobarbital revealed some striking differences. Although both alpha chloralose and the barbiturate reduced the amount of stage REM and the frequency of brief arousals, the latter compound enhanced EEG fast activity and desynchrony, and suppressed such phasic phenomena as rapid eye movements during stage REM, sigma spindles in stage 2, nonspecific electrodermal responses during SW sleep and cardio-respiratory variability in all sleep stages. For secobarbital, the decrease in percent stage REM was compensated by an increase in stage 2 rather than SW sleep. Several studies in the cat suggest that in subanesthetic doses, alpha chloralose acts primarily on cortical inhibitory processes, causing release of the reticular activating system from inhibitory influences. The results of this study show that moderate doses in man probably act on both cortical and subcortical systems involved in the mediation of SW sleep, REM sleep and arousal.
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    URL: http://dx.doi.org/10.1007/BF00410798
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    Trial of an anti-anxiety compound-Doxepin (Sinequan) (1969)
    Springer
    Psychopharmacology 15 (1969), S. 134-143 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Anti-Anxiety ; Controlled Trial ; Doxepin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Six patients with persistent anxiety symptoms were used in a preliminary assessment of a new anti-anxiety compound-Doxepin (Sinequan) with placebo. The factorial design is discussed as a potentially useful way of conducting a first-stage test of anti-anxiety compounds. Analysis of the results showed that Doxepin at 25 mg t.d.s. and 50 mg t.d.s. was associated with improvement in the patient's self ratings of anxiety symptoms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00407046
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    The behavioral effects of nicotinamide adenine dinucleotide in chronic schizophrenia (1969)
    Springer
    Psychopharmacology 15 (1969), S. 144-152 
    Details
    ISSN: 1432-2072
    Keywords: Niacin ; Nicotinamide Adenine Dinucleotide ; Schizophrenia ; Phenothiazines ; Psychopharmacology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two grams of NAD were administered orally to ten chronic schizophrenic patients for twenty-one days. Five of the patients were also receiving thioridazine. There was no gross clinical improvement noted in any of the patients despite the fact that related experiments suggested that the NAD was absorbed. In those patients who were not also receiving phenothiazines there was a distinct tendency towards increased hostility, aggressiveness and irritability beginning one week after the initiation of NAD treatment and lasting for nearly two weeks after the NAD was discontinued.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00407047
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    Dimensions of the LSD, methylphenidate and chlordiazepoxide experiences (1969)
    Springer
    Psychopharmacology 14 (1969), S. 1-11 
    Details
    ISSN: 1432-2072
    Keywords: Lysergic Acid Diethylamide or LSD ; Methylphenidate or Ritalin ; Chlordiazepoxide or Librium ; Psychopharmacology ; Alcoholism and Drug Therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Through the retrospective use of the 156 item DWM Card Sort, the experiences from a single intravenous dose of 200 mcg of LSD, 75 mg of methylphenidate (Ritalin) and 75 mg of chlordiazepoxide (Librium) were compared in a population of 99 chronic male alcoholics treated in an “LSD setting” in a double-blind study. Surprisingly, 96 of the 156 items proved significantly different among the 3 groups. LSD was unique in producing Sensory and Perceptual Distortions (including Hallucinations or Illusions), and Mystical, Religious or Paranormal Sensations. However, contrary to expectation, LSD did not uniquely produce the traditional “therapeutic” experience, but appeared to be surpassed in that area by methylphenidate. Both drugs also produced some anxiety, while chlordiazepoxide produced relaxation, and enhanced music appreciation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00401528
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    Studies of the influence of some psychotropic substances on the grooming behaviour of white mice (1969)
    Springer
    Psychopharmacology 14 (1969), S. 18-22 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Animal Behaviour ; Mice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mice were stained with pulverized charcoal and the resulting grooming behaviour observed. From 119 controls, the typical patterns indicated a late cleaning of the tail, the sacrum and the region between the ears. The following substances were tested: Imipramine, Desipramine, Trimeprimine, Amitriptyline, Nortriptyline, Chlordiazepoxide, Iproniazide, d-Amphetamine, Chlorpromazine, Haloperidol, Acetylsalicylic acid, Metronidazole. Of these Amitriptyline, Chlorpromazine, Haloperidol and Metronidazole were effective in doses less than 1/10 of LD 5.
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    URL: http://dx.doi.org/10.1007/BF00401530
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    Langfristige Verträglichkeitsprüfung mit Benperidol an der Katze (1969)
    Springer
    Psychopharmacology 14 (1969), S. 164-166 
    Details
    ISSN: 1432-2072
    Keywords: Benperidolum ; Cat ; Extrapyramidal Side Effect ; EEG ; Toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Daily doses of 1–10 mg Benperidol were given perorally to cats during 26 months. The general behaviour and the EEG were unchanged during the treatment, in particular no signs of dyskinesia were observed. After discontinuation of the administration, the behaviour and the EEG of the animals stayed normal. Thus no lasting and irreversible side effects could be observed.
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    URL: http://dx.doi.org/10.1007/BF00403690
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    Locomotor activity and anorexogenic action (1969)
    Springer
    Psychopharmacology 14 (1969), S. 248-254 
    Details
    ISSN: 1432-2072
    Keywords: Amphetamine ; Appetite Depressants ; Psychopharmacology ; Sympathomimetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A method is described with which it is possible to measure locomotor activity and food intake simultaneously in the same rat or other small animal. From a study of a number of psychomotorstimulant drugs and anorectic agents it may be concluded that locomotorstimulation and appetite-suppression are two different effects that may or may not characterize the same drug. Methamphetamine and phenmetrazine are stimulants in doses that do not inhibit food intake. Amphepramon reduced food intake in low doses but acts as a stimulant in higher doses. Chlorphemternine and phenfluramine are anorectic agents that are not stimulants, even in high doses.
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    URL: http://dx.doi.org/10.1007/BF00404223
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    Skin conductance responses to hypercapnia in man during a cycle of addiction to morphine (1969)
    Springer
    Psychopharmacology 14 (1969), S. 394-403 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Morphine ; Skin Conductance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Skin conductance changes during periods of stress induced by hypercapnia were studied during a cycle of addiction to morphine. Conductance changes were found to be dose dependent in both tolerant and non-tolerant states. The effects of morphine on skin conductance changes induced by hypercapnia were similar to those effects previously observed on changes induced by electric shock.
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    URL: http://dx.doi.org/10.1007/BF00403580
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    Effects of two phenothiazines on the Achilles-tendon reflex (1969)
    Springer
    Psychopharmacology 14 (1969), S. 417-425 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Psychoses ; Reflex, Abnormal ; Chlorpromazine ; Trifluopromazine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary According to our results in 117 subjects, recently taken medications, age and sex must be considered when duration of the Achilles-tendon reflex is used as a clinical test to assess thyroid status. Males have a shorter ATR than females. In older subjects the ATR lasts longer than in those below age 27. Fifty-two psychiatric patients before medication did not differ in ATR duration from 65 controls. However, after 28 patients took chlorpromazine and 24 received trifluoperazine, ATR was prolonged in the chlorpromazine group and shortened in the trifluoperazine group. Neither chlorpromazine concentrate, 1,800 mg, nor trifluoperazine concentrate, 180 mg, given during the first six days, affected ATR, but an additional 6,000 mg of chlorpromazine, or an additional 420 mg of trifluoperazine over the next six days, did significantly alter ATR-duration.
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    URL: http://dx.doi.org/10.1007/BF00403582
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    Doxepin and diazepam in general practice and hospital clinic neurotic patients: A collaborative controlled study (1969)
    Springer
    Psychopharmacology 15 (1969), S. 265-279 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Doxepin ; Diazepam ; Anti-Anxiety ; Antidepressant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Doxepin and diazepam were evaluated for therapeutic effectiveness in a double blind study carried out with 69 primarily anxious neurotic outpatients attending either a municipal hospital clinic or a general practitioner's office. Doxepin produced more clinical improvement than diazepam in several questionnaire clusters measuring depressive symptomatology, but not in clusters measuring anxious symptomatology. According to several outcome criteria, doxepin tended to produce more clinical improvement in general practice than in clinic patients, while diazepam produced either equal improvement in both populations or slightly more improvement in the clinic. Possibly contributing to the present results are low daily dosage of diazepam, differential pharmacological drug effects, population differences in levels of anxiety and depression, and differences in population characteristics, primarily as related to social class.
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    URL: http://dx.doi.org/10.1007/BF00401681
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    Effects of Cannabis sativa and lysergic acid diethylamide on a visual discrimination task in pigeons (1969)
    Springer
    Psychopharmacology 15 (1969), S. 1-8 
    Details
    ISSN: 1432-2072
    Keywords: Cannabis (Marihuana) ; Lysergic Acid Diethylamide ; Hallucinogens (Psychopharmacology) ; Visual Perception ; Psychopharmacology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four pigeons were trained on a visual discrimination task which required conditional responding along the independent dimensions of form and color. High doses of Cannabis sativa (marihuana) extract and lysergic acid diethylamide (LSD), which were equated on the basis of their effectiveness in suppressing responding, increased responding on a color dimension but not on a form dimension. High doses of LSD produced a decrement in discrimination performance while comparable doses of Cannabis did not effect accuracy. Treatment with Bromolysergic acid diethylamide, saline, and pentobarbital did not produce significant changes in performance. Results are discussed in terms of a break-down in stimulus control and central hallucinogenic activity.
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    URL: http://dx.doi.org/10.1007/BF00410795
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    The interaction of amphetamine and body weight on a food-reinforced operant (1969)
    Springer
    Psychopharmacology 15 (1969), S. 64-72 
    Details
    ISSN: 1432-2072
    Keywords: Amphetamine ; Dextro Amphetamine ; Psychopharmacology ; Conditioning, Operant ; Pharmacodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Bar pressing was maintained by food reinforcement of each fiftieth response (FR50 schedule). Rats were tested at 3 levels of food deprivation (60, 80 and 100% of ad libitum body weight) under three drug conditions (0, 0.2 and 0.4 mg of D-amphetamine per rat). Overall response rate was reduced by increasing doses of drug, but not significantly by deprivation, within the range studied. The components of response rate were analysed separately into the starting speed (latency of the first response of each ratio run of 50 responses) and running rate. Drug level affected running rate and first latency of the session, whereas body weight affected only first latency of the session. Only the first latency of the session showed an interaction of drug level and body weight. The lack of interaction raises the question, whether amphetamine is more properly administered as total dose per rat, rather than proportional to body weight.
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    URL: http://dx.doi.org/10.1007/BF00410802
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    Action de la psilocybine sur le comportement d'un cercopithecinae papio-papio (1969)
    Springer
    Psychopharmacology 15 (1969), S. 109-115 
    Details
    ISSN: 1432-2072
    Keywords: Psychopharmacology ; Hallucinogens ; Drug Effects ; Behavior Exploratory ; Monkeys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of Psilocybin on the behavior of the baboon Papiopapio has been studied. Animal watchfulness, as estimated from the E.E.G., is enhanced within the first five minutes after injection and then is not further modified. Psilocybin induces a decrease of spontaneous motility. Conversely, the frequency of eye movements is considerably increased. This pattern might be explained by alterations of visual perception.
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    URL: http://dx.doi.org/10.1007/BF00407043
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    Responses of neurones in cat's abducens nuclei to horizontal angular acceleration (1969)
    Springer
    Pflügers Archiv 309 (1969), S. 285-309 
    Details
    ISSN: 1432-2013
    Keywords: Labyrinthine Stimulation ; Types of Abducens Neurones ; Frequency Analysis ; Cat ; Labyrinthreizung ; Abducensneurone ; Frequenzanalyse ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single cell activity was recorded extracellularly from neurones in cat's abducens nuclei in unanesthetized, decerebrate preparations. Two types of neurones were found. i) The motoneurones (type IIA) increased their firing linearly or exponentially to contralateral constant angular accelerations and decreased firing to ipsilateral rotation. The increased frequency was maintained at a constant level without any sign of adaptation. This constant level of maximum frequency was proportional to the logarithm of the acceleration applied. No significant differences of the frequency responses of tonic and silent motoneurones were found. The conduction velocities of the axons of spontaneously firing type IIA cells were slower than in silent neurones. Electrical stimulation of the contralateral VIIIth nerve led to activation of the type IIA cells; stimulation of the ipsilateral nerve resulted in inhibition of both spontaneous discharge and antidromic invasion of the motoneurones. ii) The type IA units increased their firing rate to ipsilateral rotation and ceased to discharge in response to contralateral rotation. They never were excited antidromically by stimulation of the VIth nerve. However, they were excited by stimulation of the ipsilateral VIIIth nerve. Their possible functional role in the vestibulo-ocular system was discussed.
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    URL: http://dx.doi.org/10.1007/BF00587754
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    Die Rolle „spezifischer” und unspezifischer Afferenzen für den Antrieb der Atmung, untersucht durch Reizung und Blockade von Afferenzen an der decerebrierten Katze (1969)
    Springer
    Pflügers Archiv 312 (1969), S. 189-205 
    Details
    ISSN: 1432-2013
    Keywords: Cat ; Decerebration ; Afferents to Respiratory Centers ; Medulla Oblongata ; Reticular Formation ; Katze ; Decerebrierung ; Afferenzen zu Atemzentren ; Medulla oblongata ; Formatio reticularis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 11 intercolliculär decerebrierten Katzen wurde geziegt, daß Kälteblockade eines eng umschriebenen Feldes auf der ventralen Oberfläche der Medulla oblongata, wie früher für anaesthesierte Tiere beschrieben, zu Atemstillstand führt, wenn die kontralaterale Stelle auf der Medulla oblongata, die Sinusnerven und die Vagi ausgeschaltet sind. Zu Atemstillstand kam es auch, wenn statt der Kälteblockade 2% Novocain durch lokale Superfusion bei gleichzeitiger Gegenspülung der Umgebung mit künstlichem Liquor angewandt wurde, oder wenn ein mit 1% Novocain getränkter Tupfer lokal aufgelegt wurde. Außerdem führte Kälteblockade zu Atemstillstand, wenn durch kontinuierliche auch während der Kälteblockade anhaltende elektrische Reizung eines N. femoralis oder hinterer Lumbalwurzeln an decerebrierten Katzen oder des Hypothalamus an einer anaesthesierten Katze Steigerungen der Ventilation ausgelöst worden waren. Elektrische Reizung eines Sinusnerven führte zu Atemsteigerungen. Bei Sinusnervenreizung während eines durch Kälteblockade ausgelösten Atemstillstands kam es zu rhythmischer Atmung. Aus diesen Untersuchungen wird geschlossen, daß mit der Ausschaltung der beschriebenen Felder auf der ventralen Oberfläche der Medulla oblongata am sonst desafferentierten Tier die Gesamtheit der für die zentrale CO2-Empfindlichkeit verantwortlichen Strukturen erfaßt ist, daß nach Ausschaltung der zentralen und der peripheren Chemosensibilität eine unspezifische Aktivierung der Atmungszentren unwirksam ist und daß die Atmungszentren zur Ausbildung einer rhythmischen Atmung von spezifischen Antrieben abhängig sind.
    Notes: Summary It was shown in 11 decerebrated cats, that cooling of a small and well defined area on the ventral surface of the medulla will cause respiratory arrest if the contralateral area of the medulla, the vagi and sinus nerves are eliminated. This confirms earlier observations obtained in anesthetized cats. Apnea was also produced by local superfusion of 2% procain with simultaneous flushing of the immediate surrounding area with mock spinal fluid. Local application of a small sponge soaked with 1% procain had the same effect. Electrical stimulation of femoral nerves or posterior roots which results in hyperventilation on the decerebrated cat failed to show any effect during periods of cold blockade. There was no respiratory response to direct stimulation of the hypothalamus in an anesthetized cat during cooling. Electrical stimulation of one sinus nerve caused an increase of ventilation. Sinus nerve stimulation during apnea induced by cold blockade resulted in rhythmical respiration. It is concluded from these experiments: Blocking of the area under discussion on the ventral surface of the medulla, inhibits all structures responsible for the central CO2-sensitivity in the deafferentiated animal. There was no response to non-specific stimuli of the respiratory center after elimination of central and peripheral chemosensitivity. The respiratory centers apparently depend on specific stimuli to support rhythmical respiration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00586928
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    Räumliche summation im receptiven feldzentrum von neuronen des geniculatum laterale der katze (1969)
    Springer
    Experimental brain research 8 (1969), S. 53-65 
    Details
    ISSN: 1432-1106
    Keywords: Lateral geniculate body ; Spatial summation ; Off-center-characteristics ; Geniculate transfer ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Die räumliche Summation im receptiven Feldzentrum von Neuronen des Corpus geniculatum laterale (CG-L) wird beschrieben und mit entsprechenden Untersuchungen an retinalen Ganglienzellen verglichen. Neben größerer interneuronaler Variabilität ergeben sich ausgeprägtere Unterschiede der Summationseigenschaften der on-und off-Zentrum-Neurone. Der effektive Summationsbereich von etwa 1/5 der Fläche des RFZ ist in Retina und CGL etwa gleich. 2. Die on-Zentrum-Neurone des CGL zeigen in beiden Adaptationszuständen einen ähnlichen Summationsverlauf wie in der Retina. Das Entladungsnieau ist im CGL jedoch erheblich geringer und nicht durch Unterschiede in der Spontanaktivität zu erklären. 3. Die Mehrzahl der off-Zentrum-Neurone des CGL zeigt bei DA inverse Summationsverläufe wie in der Retina: durchgehende Verminderung der Entladungsrate der off-Antworten bei Vergrößerung der Reizfläche im RFZ. Eine kleine Gruppe zeigt einen parabelförmigen Summationsverlauf mit Entladungszunahme bis zu Reizflächen von 10–30% der Fläche des RFZ und darauffolgender Entladungsminderung. Bei Helladaptation zeigen fast alle off-Zentrum-Neurone diesen Parabelverlauf. Das durchschnittliche Entladungsniveau ist von dem retinaler offZentrum-Neurone nicht signifikant verschieden. 4. Die interneuronale Variabilität der Summationsvorgänge im RFZ von CGLNeuronen ist gegenüber den retinalen Ganglienzellen deutlich größer. Dies gilt insbesondere für die off-Zentrum-Neurone. Das Summationsverhalten von CGLNeuronen läßt sich daher nicht wie in der Retina durch einen Funktionstyp beschreiben. 5. Die Befunde sprechen für eine Transformation des retinalen Eingangs der off-Zentrum-Neurone im CGL, während die on-Zentrum-Neurone außer der bekannten Frequenzuntersetzung keine wesentliche Umformung erkennen lassen.
    Notes: Summary 1. Spatial summation in the receptive field center of neurones of the lateral geniculate body (CGL) is limited by inhibition to a small part of field center. Variations of stimulus size are only effective if the stimulus is smaller than about 1/5 of the area of receptive field center. Thus, the active summating area of the field center in the CGL corresponds to that of the retina. Geniculate neurones, however, show less homogeneous responses and the summation properties of the two neuronal subsystems (on-center-and off-center-cells), show greater differences than in the retina. 2. The form of summation curves for the on-center-neurones of the CGL is similar to those of the retina at both adaptation levels. However, the average responses rates in the CGL are considerably lower. This is not due to differences of spontaneous activity. 3. The summation characteristics of off-responses of off-center-neurones of the CGL are quite different from those in the retina. In dark adaptation the majority of CGL neurones respond with decreasing discharge rates to increasing spot-sizes within the field center. A small number show an initial increase of discharge rates up to stimulus sizes of about 1/10 of the receptive field center before a decrease occurs. This parabolic summation type is typical for most off-center-neurones in light adaptation. The mean discharge levels are the same as those of the retinal offcenter-neurones. 4. The higher interneuronal variability of summation curves especially of the off-center-neurones of the CGL indicates a more complex determination of the discharge properties of CGL neurones. This functional differentiation of single neurones is congruent with the more complex structural and synaptic organisation in CGL. 5. With respect to spatial summation, the results indicate a transformation of the retinal input of the off-center-neurones at the geniculate level, whereas the oncenter-neurones are nearly unchanged.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234925
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    Räumliche summation und hemmungsvorgänge im receptiven feldzentrum von retina-neuronen der katze (1969)
    Springer
    Experimental brain research 8 (1969), S. 37-52 
    Details
    ISSN: 1432-1106
    Keywords: Retinal Ganglion Cells ; Spatial Summation ; Center Inhibition ; Dynamic Organisation of Receptive Fields ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. An retinalen Ganglienzellen der Katze wurde die räumliche Summation im receptiven Feldzentrum (KFZ) bei Dunkeladaptation und Helladaptation durch mittelpunktzentrierte Lichtreize verschiedener Flächengrößen untersucht. Als Kriterium dienten die Entladungsraten der ersten 200 und 500 msec nach Licht-an oder Licht-aus. Das Summationsverhalten wurde sowohl für Einzelneurone als auch gruppenstatistisch für die beiden Neuronen-Systeme B (on-Zentrum) und D (off-Zentrum) untersucht. 2. Die räumliche Summation ist auf den inneren Bereich des RFZ beschränkt: bei on-Zentrum-Neuronen steigt die Entladungsrate nur bis zu Reizflächen, die etwa 1/5 der Fläche des RFZ belichten, bei off-Zentrum-Neuronen bis zu Reizflachen von ca. 1/10 des RFZ. Bei Variation der Reizfläche zwischen 20 und 100% der Fläche des RFZ bleibt das Entladungsniveau konstant (asymptotischer Verlauf der Summationskurve). 3. Die Begrenzung der räumlichen Summation auf einen kleinen Bereich des RFZ beweist eine bereits im Feldzentrum wirksame Hemmung. Diese Zentrum-Inhibition begrenzt die Erregungssummation im RFZ bei zunehmender Flächengröße des Lichtreizes. 4. On- und off-Zentrum-Neurone unterscheiden sich in beiden Adaptationszuständen in der Höhe des Entladungsniveaus. Die Entladungsraten der on-Zentrum-Neurone nach Licht-an übertreffen um ein Mehrfaches die Entladungsraten der off-Zentrum-Neurone nach Licht-aus. Die Unterschiede sind gruppenstatistisch hoch signifikant. Die interneuronale Variabilität der Entladungsraten ist bei den onZentrum Neuronen erheblich geringer als bei den off-Zentrum-Neuronen. 5. Dunkel -und Helladaptation führt zu signifikantem Unterschied der Entladungsraten: bei Helladaptation liegt die Impulsrate beider Neuronentypen höher als bei Dunkeladaptation und der Summationsbereich ist um 5–10% größer. 6. Für die mathematische Beschreibung der Summationsverläufe ist die Hyperbel besser geeignet als die logarithmische und Potenzfunktion. Logarithmus- und Potenzfunktionen beschreiben den konstanten asymptotischen Teil der Summationskurven ungenügend und eigenen sich nur für den Kurventeil im innersten Summationsbereich. Die Bedeutung der Befunde für eine dynamische Interpretation der visuellen Feldorganisation und mögliche Beziehungen zur lateralen Umfeldhemmung werden diskutiert.
    Notes: Summary 1. Spatial summation of suprathreshold light stimuli within receptive field centers (RFZ) of retinal ganglion cells was investigated during dark and light adaptation in cats. The mean discharge rates for 200 and 500 msec following light on or off were the computed response criteria. The summation effects were analyzed for single neurones and statistically for grouped neuron populations of the two neuronal subsystems B (on-center-neurones) and D (off-center-neurones). 2. Spatial summation is restricted to a small part of the RFZ. On-centerneurones increase their on-discharge rates with increasing spot sizes, only if the stimulus illuminates less than 1/5 of the RFZ. The summating area of the off-centerneurones is smaller (about 1/10 of the RFZ). 3. The limitation of spatial summation to a small part of the RFZ indicates the existance of inhibition within the RFZ. This center-inhibition sets a constant limit for excitation summation in the RFZ. 4. The mean neuronal response rates for the 2 subsystems show significant differences: The on-discharges of the on-center-neurones exceed the off-discharges of the off-center-neurones by a factor of 3–5. These highly significant differences occur at both adaptation levels and are not due to different spontaneous activity. Interneuronal response variability of the off-center-neurones was twice as large as that of the on-center-neurones. 5. Change from dark to light adaptation had only a small but significant influence on summation properties. The poststimulus discharge rates were higher during light adaptation and the summating area was slightly larger (about 5–10%). 6. A comparative curve fitting procedure for three suitable mathematical functions revealed that the hyperbola describes the neuronal summation curves better than a logarithmic or power function. The latter do not fit the constant asymptotic part of the curve. The significance of the results for a dynamic interpretation of the organisation of visual receptive fields is discussed.
    Type of Medium: Electronic Resource
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    Polyamides in solution. III. Viscometry of linear polycaprolactam (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 411-422 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The viscometric behavior of linear polycaprolactam has been studied in the absence of the electroviscous effect in aqueous solvents containing 85% and 64.5% formic acid and in trifluoroethanol, as a function of temperature and also under unperturbed conditions. Results are discussed in terms of the existing theories; in particular, the negative temperature coefficient of the intrinsic viscosity arises only from the variation of the expansion coefficient, the molecule in the unperturbed state being a normal random coil. The absence of aggregation and draining effects in the above solvents has been varified.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1969.160070212
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    Polymerization of cyclic imino ethers. VI. X-ray study of some polyaziridines (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 463-473 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polymers of poly(N-acyl and N-aroyl aziridines) were studied by x-ray diffraction. All the crystalline polymers studied have a triclinic unit cell with two monomer units per unit cell. The a and c (fiber direction) parameters (4.9 and 6.5 A, respectively) are essentially the same for all the cells. The b parameter for the N-acyl polymers, however, increases steadily by a factor of 2 A per methylene group added to the lateral chains. The densities calculated for the unit cells are in agreement with the experimental values obtained. The most probable structure is one in which the molecules assume a planar configuration with the main chain not fully extended. The lateral groups are tilted from the c axis by an angle of 54° in a parallel configuration and alternate on each side of the main chain. This permits these lateral groups to assume packing similar to that of polyethylene. A brief description of the techniques used in this interpretation is included.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070302
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    Energy dissipation by pulsating air bubbles in a viscoelastic medium (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 143-151 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A theoretical discussion is presented on the mechanisms by which an isolated pulsating air bubble in a viscoelastic solid dissipates its energy. The analysis is limited to the situation where the amplitude of motion is assumed to be sufficiently small that the stress strain relations may be described by linear equations with convected differentiation replaced by ∂/∂t. The theoretical thermal, radiation, and viscous damping constants are calculated for resonant air bubbles in unvulcanized natural rubber; however, the results are typical of elastomers in general.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070111
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    Form birefringence in biaxially oriented polypropylene (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 231-240 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The birefringence of several biaxially oriented polypropylene films swollen with a number of fluids has been measured and found to exhibit a minimum when plotted against the fluid refractive index, as predicted by the theory of Wiener. However, a discrepancy in the form birefringence behavior is observed when samples of different degrees of crystallinity but the same total birefringence are compared. These results are interpreted in terms of Bullough's theory and suggest that this discrepancy arises because of different morphologies. A refractometric technique was employed that makes possible the simultaneous determination of birefringence and the volume fraction of fluid.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070119
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    Crystallite orientation in stretched polychloroprene networks. II (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 257-270 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The orientation of crystallites grown isothermally in several drawn trans-polychloroprene networks is studied as a function of crystallization temperature tx, degree of crystallinity ω, and elongation ratio α. The orientation distribution is particularly simple for this polymer since the crystallographic c axis (chain axis) orients preferentially along the stretching direction, while a and b are randomly arranged about c. Hence the parameter cos2 χc adequately characterizes the distribution, where χc is the angle between the c axis and the fiber axis, and the average is taken over all crystallites. A treatment due to Krigbaum and Roe is utilized to obtain values of v (the number of statistical segments comprising the crystallization nucleus of critical size) through comparison of the average orientation of crystallites and amorphous statistical segments. The behavior observed falls into two categories. First, if the initial amorphous network is well oriented, 〈cos2 χc〉 is independent of crystallinity during both crystallization and melting, and v varies with tz (or the degree of supercooling) as predicted by nucleation theory. If different networks are to have the same crystallite orientation distribution, they must not only be crystallized at the same supercooling, but must also have the same distribution of amorphous segment orientations. Both the relative elongation and the network crosslink density affect the latter distribution. Next, we consider the second category. If the initial amorphous orientation is poor, 〈cos2 χc〉 decreases linearly during crystallization and increases along approximately the same path during melting. Further, 〈cos2 χc〉 for a given tz yields v values which are too large. These two behaviors can be explained if, in the former case, nucleation involves the best oriented statistical segments of all network chains, while in the latter there is a selection according to the chain displacement vector orientation. Thus, if the amorphous orientation is poor, both the orientation and thermodynamic stability of the crystallites decreases with further crystallization. If this decreased stability is reflected in shorter fold lengths, the reversible variation of long period spacing with temperature reported earlier for an oriented polychloroprene network can also be explained as a preferential melting process.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070201
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    Differential thermal analysis of polyethylene under high pressureThis paper was presented in part at the 1966 IUPAC meeting in Tokyo and Kyoto. (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 377-388 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The design of a differential thermal analysis apparatus for use at elevated pressure is described. Experiments on melting and crystallization of folded-chain crystals of polyethylene and poly(ethylene-butene-1) copolymer, and melting of extended-chain polyethylene crystals have been conducted at pressures up to 4200 bars. The precision in transition temperature measurement was ±1°C. The Clausius-Clapeyron equation predicts the melting point increase with pressure at atmospheric pressure to be 32.0°C/kb. The melting point depression due to copolymerization remained constant over the complete pressure range analyzed on the poly(ethylene-butene-1) used in this study. Crystallization of polyethylene is retarded at elevated pressures, and a 50% larger degree of supercooling is necessary at 5000 bars to give a crystallization rate equal to that observed at atmospheric pressure. The difference in melting point between folded-chain and extended-chain polyethylene increases from 8.4°C at 1 bar to 25.6°C at 3000 bars.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1969.160070209
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    Conformational energy contribution to the heat of solution in polymer-solvent systems. Part I. Theory (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 845-853 
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    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The conformational energy contribution (ΔUconf) to the heat of solution in polymer-solvent systems is presented and discussed in connection with chain conformational properties. In particular, ΔUconf has been discussed in terms of various possible mechanisms of coil deformation.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1969.160070509
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    Effect of induced thermal stresses on the coefficients of thermal expansion and densities of filled polymers (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 889-896 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It is demonstrated that in a filled polymer the thermal stresses resulting from the difference in the thermal expansion coefficients of the filler and the polymer have significant effect on the apparent coefficient of thermal expansion of the composite. A model is constructed to aid the thermal stress analysis, and the results are found to agree well with the experimental data obtained from other sources. An expression for the apparent densities of filled polymers is also obtained but the agreement between the present prediction with an existing test result is found to be only qualitative.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1969.160070513
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    Diffusion and solubility of methane in polyisobutylene (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 947-962 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Diffusion coefficients and solubilities of methane in polyisobutylene have been measured at four temperatures between 102 and 188°C. in the pressure range 23-341 atm. Diffusion coefficients extrapolated to atmospheric pressure range from 1.72 × 10-6 cm.2/sec. at 102°C. to 1.5 × 10-5 cm.2/sec. at 188°C. corresponding to an activation energy for diffusion of 8.7 ± 0.4 kcal./mole. Solubilities are small, about one molecule of methane for every forty carbon atoms in the polyisobutylene at 300 atm. partial pressure of methane. Solubilities vary little with temperature, but show an apparent minimum between 127 and 188°C. With improved methods of data analysis, diffusion coefficients and solubilities have been recalculated from previously reported studies on nitrogen in branched polyethylene and methane in branched polyethylene, linear polyethylene, and polystyrene. Recalculated diffusion coefficients are essentially the same as those reported previously, but the recalculated solubilities are decreased from 2 to 30%. The solubilities of all five systems show strong deviations from Henry's law, i.e., increases in partial pressure of methane and nitrogen with respect to solubility exceed linearity. The partial pressure (or fugacity) - solubility data may be interpreted in terms of a sorption model in which sorbed molecules are accommodated in widely dispersed, unoccupied volumes or sites in the polymer. An almost equivalent, solution model in which the first sorbed molecules to enter the polymer are accommodated to a large extent in existing volumes in the polymer, with successively sorbed molecules swelling the polymer to a greater extent (i.e., partial molal volume of sorbed molecules, V1, increasing with concentration) can also account for these data.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1969.160070517
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    Effect of monofunctional reactants on gel point in polycondensation reactions (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1116-1118 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070612
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    Effect of finite extensibility on the viscoelastic properties of a styrene-butadiene rubber vulcanizate in simple tensile deformations up to rupture (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 635-658 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Stress-strain and rupture data were determined on an unfilled styrene-butadiene vulcanizate at temperatures from -45 to 35°C and at extension rates from 0.0096 to 9.6 min-1. The data were represented by four functions: (1) the well-known temperature function (shift factor) aT; (2) the constant strain rate modulus, F(t,T), reduced to temperature T0 and time t/aT, i.e., T0F(t/aT)/T; (3) the time-dependent maximum extensibility, λm(t/aT); and (4) a function Ω(χ) where χ = (λ - 1)λm0/λm, in which λ is the extension ratio and λm0 is the maximum extensibility under equilibrium conditions. The constant strain rate modulus characterizes the stress-time response to a constant extension rate at small strains, within the range of linear response; λm is a material parameter needed to represent the response at large λ; and Ω(χ) represents the stress-strain curve of the material in a reference state of unit modulus and λm = λm. The shift factor aT was found to be sensibly independent of extension. At all values of t/aT for which the maximum extensibility is time-independent, the relaxation rate was also found to be independent of λ. These observations indicate that the monomeric friction coefficient is strain-independent over the ranges of T and λ covered in the present study. It was found that λm0 = 8.6 and that the largest extension ratio at break, (λb)max, is 7.3. Thus, rupture always occurs before the network is fully extended.
    Additional Material: 17 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1969.160070404
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    Ultimate tensile properties of elastomers. VI. Strength and extensibility of a styrene-butadiene rubber vulcanizate in equal biaxial tensionPresented at the San Diego Meeting of the Society of Rheology, February 5-7, 1968. (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 687-707 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The ultimate properties of an unfilled styrene-butadiene rubber vulcanizate in equal biaxial tension were determined by inflating a circular membrane into a bubble. Tests were made at several extension rates (evaluated at the pole) from about 0.15 to 4 min-1 and at temperatures from -43 to 90°C. The stress in the vicinity of the pole when rupture occurred was evaluated from the pressure, the radius of curvature, and the extension ratio λ, the latter two quantities being obtained from photographic data. Below 70°C, the ultimate extension ratio λb is approximately 5.2 and is essentially independent of extension rate and temperature, in striking contrast to the behavior in simple and constrained biaxial tension (pure shear). Likewise, the rupture stress is manyfold greater than in either simple or constrained biaxial tension. From the extremum points of failure envelopes, the maximum extension ratio (λb)max in equal biaxial tension is 5.7 and in simple tension is 7.2. An examination of ruptured membranes showed that, except at 70 and 90°C, rupture began away from the pole in a region where the stress state is unequal biaxial tension. Hence, values of the ultimate properties in truly equal biaxial tension are no doubt somewhat greater than those obtained from the membrane tests. However, it is shown that (λb)max in truly equal biaxial tension must be lower than that in simple tension by at least 10%. A consideration of rupture data in simple, constrained biaxial, and equal biaxial tension leads to the conclusion that no simple failure criterion is applicable for interrelating data obtained under the several states of combined stress. The rupture patterns and factors that affect the site of rupture initiation and the mode of crack growth are also discussed.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070408
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  • 87
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    Tensile yield-stress behavior of glassy polymers (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 735-742 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It is shown that, at the yield stress, glassy polymers exhibit viscous flow which is in agreement with the generalized theory of Eyring. The study of the yield stress over a wide range of temperatures and strain rates provides evidence on the secondary transitions found by other methods. From our measurements we conclude that every secondary transition corresponds to the liberation of one of the degrees of freedom of a segment of the main chain.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070411
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  • 88
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    Gel permeation chromatography studies of the degradation of polythylene with fuming nitric acid. III. Fibrous stirring-induced crystals (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 751-751 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070417
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  • 89
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    Lactone polymers. I. Glass transition temperature of poly-ε-caprolactone by means on compatible polymer mixtures (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 795-807 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dynamic mechanical properties determined with a torsion pendulum were used to ascertain the glass transition temperature Tg of poly-ε-caprolactone. By measurements on compatible blends of poly-ε-caprolactone and poly(vinyl chloride), the Tg of amorphous poly-ε-caprolactone was shown to be 202°K at about 1 cps. This is 16°K lower than the Tg of annealed, crystalline polymer. The blend transition data were well fitted by both the Fox and the Gordon-Taylor expressions. The Fox expression was also used to describe the decrease from 233°K of the secondary low-temperature relaxation due to poly(vinyl chloride) by assuming the low temperature relaxation of poly-ε-caprolactone, 138°K, was responsible for the decrease in the blends. The 138°K relaxation due to poly-ε-caprolactone was decreased when more than 50% poly(vinyl chloride) was present.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070505
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  • 90
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    Yielding of oriented poly(vinyl chloride) (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 829-844 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly(vinyl chloride) sheet was oriented by hot drawing. The yield behavior of the oriented sheet was then investigated under uniaxial tension at room temperature as a function of the angle between the tensile axis and the molecular alignment direction. The onset of yield was localized in deformation bands. The variation of yield stress with direction and the direction in which the deformation bands formed were found to be satisfactorily accounted for in terms of a yield criterion based on that of von Mises, provided that a term representing internal compressive stress in the molecular alignment direction was included. The internal stress was found to increase from zero with increasing draw ratio of the prior hot drawing. It is pointed out that other workers have found polymers to obey the yield criterion of Coulomb rather than that of von Mises.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070508
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  • 91
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    Diffusion in glassy polymers. II (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 879-887 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Fickian diffusion coefficient of methylene chloride in a glassy epoxy polymer is calculated with the use of Crank's model of discontinuous change of D with concentration C. The diffusion constant is obtained as 1.93 × 10-6 cm2/sec. The swollen layer behind the advancing solvent front is essentially in the rubbery state of the same polymer. The case II swelling by benzene is discussed in terms of a convective transport arising from the partial stress (internal) tensor of the penetrant. The superposition of Fickian and case II diffusion found with mixtures of methylene chloride and benzene is also discussed briefly.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070512
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  • 92
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    Dilute solution properties of poly(α-methylstyrene-ethylene) “regular” sequence copolymers (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 929-945 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: “Regular” sequence copolymers having the structure {[—CH2—C(CH3)(C6H5)—]m(CH2—CH2)n}p with relatively small values of m and n were prepared by means of “living” polymerization techniques. The intrinsic viscosities of fractions of these copolymers were obtained in various solvents including a theta solvent. The molecular weights of these fractions were determined by the Archibald ultracentrifugal method. The results show that the intrinsic viscosity-molecular weight relations of the regular sequence copolymers are affected not only by the average composition of the copolymer, but also by the sequence length in the copolymer molecule. It is suggested that the effective conformation of a chain element in the copolymer is not always the same as that in the homopolymer.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070516
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  • 93
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    Effects of ultraviolet radiation on aqueous polyelectrolyte solutions (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 993-1003 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effects of ultraviolet radiation on dilute aqueous solutions of poly(acrylic acid) and of other polyelectrolytes were studied by viscosity measurements in connection with the effects of ionizing radiation. It was found that ultraviolet light of wavelength below about 2300 Å brought about degradation of polymer chains mainly by indirect action via water, while light of wavelength above 2300 Å caused degradation by direct action in some polymers. It was deduced from the experiments that the protective effect of NaCl could be largely attributed to a decrease in the indirect action. It was also found that a low concentration of methanol was effective in preventing degradation by direct action, although methanol promoted degradation when present in high concentration. Since the promotive effect was not observed when light of wavelength below 3700 Å was eliminated by a filter, this effect was attributed to active products of the irradiation of methanol.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070603
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  • 94
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    Raman spectra of extended-chain syndiotactic poly(vinyl chloride) (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1075-1084 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman spectra have been obtained for a typical poly(vinyl chloride) (PVC) of low crystallinity and for a highly crystalline sample of syndiotactic PVC obtained by irradiation of a urea-canal complex. Raman measurements have been made on the three different ordered chain structures possible for ordinary PVC. Extended and folded conformations for the syndiotactic structure and a helical structure for the isotactic molecule obey different selection rules and have different dichroic properties in the infrared and Raman spectra. The observed Raman spectrum is consistent with the model of the extended syndiotactic conformation for crystalline PVC. With the new Raman data some additional assignments can be made in the vibrational spectra of PVC.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070608
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  • 95
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    Swelling of crosslinked poly-4-vinylpyridine (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1101-1109 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polyvinylpyridine of molecular weight 0.77 × 106 was crosslinked by 2.5, 5, and 10% BrCH2C6H4CO(CH2)8COC6H4CH2Br and by 10% ClCH2C6H4CH2Cl; quaternization of the gel was completed with n-butyl bromide. Swelling ratios in aqueous solutions of lithium, sodium, and 4-isopropyl-N-n-butylpyridinium bromide and in methanolic lithium bromide were determined. Selectivity increased in the sequence Li+ 〈Na+ 〈PrN+-C5H5. The Flory parameter χ1, which measures interaction between solvent and polymer, decreased from 1.5 kT to nearly zero with increasing density of crosslinks in the aqueous solutions, and from 3 kT to 0.5 kT in the methanol solutions. The inverse proportionality of q2/3 (q = swelling ratio) to the crosslinking density was approximately verified for swelling of the resins in water, methanol, and dimethylformamide.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070610
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  • 96
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    Electronic Resource
    Effects of catalyst heterogeneity on polymer tacticity (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1111-1115 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070611
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  • 97
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    Spherulitic crystallization studies of poly(tetramethyl-p-silphenylene)-siloxane (TMPS). Part III (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1187-1195 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Extensive studies of the kinetics of spherulitic crystallization have been made on fractionated samples of TMPS. An analysis of these results reveals that a two-dimensional growth rate mechanism is a more likely mode of growth than a three-dimensional one. This conclusion is substantiated by experimental evidence from optical microscopy and light scattering from within spherulites. The crystallite end surface energy is found to increase as the molecular weight is raised.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070704
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  • 98
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    The limiting axial long period of drawn polypropylene (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1275-1278 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070707
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  • 99
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    Electronic Resource
    Effect of molecular weight on the radial growth rates of polymer spherulites (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1883-1894 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Data existing in the literature for the spherulitic growth rate of molecular weight fractions of linear polyethylene, poly-(tetramethyl-p-silphenylene)siloxane, and trans-1,4-polyisoprene have been analyzed according to nucleation theory on taking into account the influence of chain length on the free energy of fusion. All three polymers display very similar behavior in that the interfacial free energy reaches an asymptotic value at high molecular weights, decreases as the molecular weight is lowered, and appears to also reach an asymptotic value at low molecular weights. Although the changes in the interfacial energy with molecular weight are quite distinct, the relative change is much less than has been previously reported when a molecular crystal analysis is used. The same general behavior observed points out the dominating influence of the chain-like character of the molecules in governing the growth rate.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160071104
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  • 100
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    Studies of branching in polyvinyl acetate (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1919-1935 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Batch polymerizations of vinyl acetate were conducted at 60°C and 72°C, and rate constants for branching were established from the variation of M̄n and M̄w with extent of conversion. The calculated branching densities (branch points per polymer molecule) are slightly higher at 72°C for all conversions. Selected samples were saponified and reacetylated to determine the amount of branching through the acetate group. Changes in M̄n, M̄w, and [η] indicate 63%, 75%, and 70%, respectively, of saponificable branches. These percentages are independent of branching density in the original polymer. Molecular weights extrapolated to zero conversion appear to be unchanged by saponification and reacetylation, showing that short chain branching through the acetate group is absent, or at least very infrequent.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160071107
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