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  • 1985-1989
  • 1970-1974  (181)
  • 1972  (181)
  • Ultrastructure  (115)
  • Rat  (73)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 274 (1972), S. 357-374 
    ISSN: 1432-1912
    Keywords: Intestinal Blood Flow ; Blood-to-Lumen Flux ; Tritiated Water ; Solvent Drag ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Anaesthetized rats were loaded with tritiated water and a jejunal loop was perfused with hypo-, iso-, and hypertonic buffered saline solutions. The blood flow, the disappearance rate (from the blood), and the appearance rate (in the intestinal lumen) were determined simultaneously. 2. A decrease of the blood flow from about 1.7 to 0.2 ml min−1g−1 wet tissue weight diminished both the appearance rate and the disappearance rate of tritiated water. An increase of the blood flow caused the reversed results; however, at high blood flow the appearance and disappearance rate did not reach the value measured in the experiments with decreasing blood flow. 3. A water net flux directed towards the blood retarded and towards the intestinal lumen accelerated the blood-to-lumen flux of tritiated water at low, intermediate, and high blood flow values. 4. The data were analysed by a modified four-compartment-model considering the variation of blood flow and water net flux. The water net flux influences the blood-to-lumen flux of tritiated water by solvent drag during the penetration through the epithelium and by changing the luminal concentration (e.g. dilution) as well as the blood flow rate in the capillaries near the epithelium.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 202 (1972), S. 21-36 
    ISSN: 1432-1459
    Keywords: Hydrocephalus, Experimental ; Ethylnitrosourea ; Experimental Hydrocephalus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 25 mg/kg Äthylnitrosoharnstoff wurden am 9 1/2. Tag der Schwangerschaft SD-JCL-Ratten injiziert. Die Feten wurden am Termin excidiert und mit dem Stereomikroskop untersucht. 78% der Feten zeigten einen Hydrocephalus. Die histologische Untersuchung in Stufenschnitten des Gehirns zeigte eine Stenose des Aquädukts ohne subependymale Gliose, ödematöse Plexus chorioidei mit prallgefüllten Gefäßen, spärlichem Bindegewebe und geschwollenen Epithelzellen, Verdünnung der telencephalen Wandungen mit schwach entwickelter granulärer Schicht und in der ependymalen Zone verbleibenden Neuroblasten. Die Entwicklung der jungen Ratten wurde studiert. 75% der neugeborenen Ratten zeigten klinisch gewisse Hinweise auf den Hydrocephalus. Stark betroffene Tiere wurden zunehmend somnolent und/oder gelähmt und starben meist vor Ende der 4. Woche. Der Eiweißgehalt des Liquors war nennenswert vermehrt. Es wurden subdurale, subarachnoidale und intraventrikuläre Blutungen beobachtet und als wahrscheinliche Todesursache angesehen. Die histologische Untersuchung der hydrocephalen Jungtiere ergab eine Abflachung der Ependymzellschicht und pralle Füllung corticaler Gefäße von der 2. Woche an. In späteren Stadien wurde eine Dickenabnahme der periventrikulären weißen Substanz, im besonderen im Bereiche des Occipitalhornes nachgewiesen. Im verdünnten Pallium waren Vacuolenbildungen des perineuralen Gewebes zu sehen, Verbreiterung der Virchow-Robinschen Räume und eine dem Status spongiosus ähnliche Degeneration. Verschiedene Formen ependymaler Wucherung wurden gesehen. Die vorliegende Studie stellt die erste postnatale Beobachtung von transplacentar verursachtem kongenitalem Hydrocephalus in der Ratte dar. Die hier beschriebene Technik erwies sich als einfaches und reproduzierbares Mittel, um einen kongenitalen Hydrocephalus in der Ratte zu erzeugen.
    Notes: Summary SD-JCL rats were injected with 25 mg/kg of ethylnitrosourea on day 9 1/2 of gestation. Fetuses were excised near term and examined under dissecting microscope. 78% of viable fetuses were found to be hydrocephalic. On the histologic study of the serial sections of the brain, a stenosis of the Sylvian aqueduct without subependymal gliosis, edematous choroid plexus with engorged vessels, scanty connective tissue and swollen epithelium, thinning of the telencephalic wall with poorly developed granular layers and the neuroblasts remaining in the ependymal zone, were the characteristic findings in the hydrocephalic fetuses. The natural course of the treated young rats was studied. 75% of the newborn rats showed some clinical evidence of hydrocephalus. Severely affected rats became progressively lethargic and/or paralytic, and died usually before the end of 4th week. Protein content of the cerebrospinal fluid was significantly increased. Subdural, subarachnoid and intraventricular hemorrhages were observed and suspected to be the cause of death. On the histological examination of hydrocephalic youngs, flattening of the ependymal cells and engorgement of the cortical vessels were observed as early as in 2-week-old youngs. In more advanced stages, there was noted the thinning of the periventricular white matter, especially around the occipital horn. The thin pallium showed vacuolization of the perineural tissue, enlargement of the Virchow-Robin space and the status spongiosus-like degeneration. Various types of ependymal proliferation was seen. The present study represents the first postnatal observation of the transplacentally induced congenital hydrocephalus in the rat. The present technique proved to be a simple and reproducible model of producing a congenital hydrocephalus in the rat.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 10 (1972), S. 38-48 
    ISSN: 1432-0827
    Keywords: Bivalve ; Molluse ; Shell ; Carbonates ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La technique du bombardement à l'aide d'ion d'argon est utilisée pour réduire l'épaisseur de la coquille de carbonate de calcium des bivalvesMytilus etMercenaria pour examen au microscope électronique par transmission et en diffraction électronique; une comparaison est réalisée à l'aide de répliques simples, servant de témoins. Les résultats obtenus confirment les études antérieures de répliques et de microscopie par balayage. De plus, une structure “aérée” est mise en évidence dans la coquille des aragonites, et surtout dans le nacre deMytilus. Cette structure est interprêtée comme un artefact induit par la chaleur, formé par l'inclusion d'eau et de matériel organique, interprétation qui concorde avec les études chimiques et de microscopie électronique.
    Abstract: Zusammenfassung Die Beschießung mit Argonionen wurde angewendet, um die Dicke von Calciumcarbonat-Schalen der zweischaligen MuschelnMytilus undMercenaria zu reduzieren. Diese Technik erlaubte die Ausführung von Transmissions-Elektronenmikroskopie und Elektronendiffraktion, wobei gleiche Proben nach einer bereits bestehenden Methode vorbereitet und als Kontrollen herangezogen wurden. Es wurden zusätzliche Resultate zu den Muschelstruktur-studien erhalten, welche früher publizierte Arbeiten unterstützen, die mit der Abklatschmethode und der Raster-Elektronenmikroskopie ausgeführt worden waren. Zusätzlich wurde eine „schaumartige” Struktur der Muschelaragoniten, besonders im Perlmutter vonMytilus, beobachtet. Da es sich um ein durch Hitze verursachtes Artefakt handelt, wird diese Struktur als Einschlüsse von Wasser und organischem Material interpretiert, was den Befunden von verschiedenen veröffentlichten chemischen und elektronenmikroskopischen Arbeiten entspricht.
    Notes: Abstract Use is made of the argon ion-bombardment technique to reduce the thickness of calcium carbonate shells of the bivalvesMytilus andMercenaria for transmission electron microscopy and electron diffraction, with comparison of single-stage replicas of similar specimens serving as controls. As an additional approach to shell structure studies, it gives results which support earlier published work with both replicas and scanning microscopy. In addition, a “frothy” structure is detected in the shell aragonites, especially inMytilus nacre. As a heat-induced artifact, it is interpreted as representing trapped water and organic material inclusions, an interpretation consistent with several published chemical and electron microscope studies.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 10 (1972), S. 216-222 
    ISSN: 1432-0827
    Keywords: Ultrastructure ; Callus ; Osteoclast ; Endocytosis ; Lysosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La bordure en brosse des ostéoclastes de cals de fractures de rats présente des plissements complexes de la membrane cytoplasmique formant des canaux étroits. L'absorption d'un produit exogène opaque aux électrons (des macromolécules de dioxyde de thorium) s'effectue par l'intermédiaire de ces canaux, par un «courant» membranaire. Les contenus des canaux sont transférés à des lysosomes («granules spécifiques»), situés sous la bordure en brosse. Dans des «régions de transition», adjacentes à cette dernière, l'absorption de dioxyde de thorium se fait par «vésiculation membranaire» (endocytose classique).
    Abstract: Zusammenfassung Der gekrauste Rand der Osteoklasten im Frakturcallus von Ratten besteht aus komplexen Einstülpungen der Plasmamembran, die enge Kanälchen bildet. Die Absorption einer exogenen, elektronisch dichten Verbindung, Thoriumdioxyd, erfolgt durch diese Kanäle, offenbar durch einen „Membranfluß”. Der Inhalt der Kanäle wird zu den Lysosomen („spezifische Granula”) geführt, welche unter dem gekrausten Rand liegen. In „Übergangsgebieten”, welche sich neben dem gekrausten Rand befinden, scheint die Aufnahme der Thoriumdioxydpartikel durch „Bläschenbildung in der Membran” (konventionelle Endocytose) stattzufinden.
    Notes: Abstract The ruffled border of osteoclasts in the fracture callus of rat consists of complex infoldings of the plasma membrane forming narrow channels. Absorption of an exogenous, electron-dense compound, thorium dioxide, has been shown to take place via these channels, apparently through “membrane flow”. The contents of the channels are transferred to lysosomes (“specific granules”) located subjacent to the ruffled border. In “transitional regions” adjacent to the ruffled border, uptake of thorium dioxide particles appeared to occur through “membrane vesiculation” (conventional endocytosis).
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 10 (1972), S. 238-251 
    ISSN: 1432-0827
    Keywords: Growth ; Bone ; Rat ; Tetracycline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La vitesse de croissance normale en longueur de la métaphyse proximale du tibia est déterminée chez le rat Sprague-Dawley entre les âges de 20 et 100 jours, en utilisant la méthode à la tétracycline. Le taux de croissance ne varie que légèrement dans les groupes d'âges différents. Il est plus élevé chez les animaux jeunes et décroit considérablement en fonction de l'augmentation de l'âge. Les rats mâles présentent une croissance plus élevée que les femelles. Cette étude a pour but de mettre au point une méthode permettant de déterminer les facteurs expérimentaux, liés à la croissance en longueur du rat.
    Abstract: Zusammenfassung Die normale Längenwachstums-Geschwindigkeit der proximalen Wachstumsplatte der Tibia wurde bei Sprague-Dawley-Ratten in einem Alter zwischen 20 und 100 Tagen mittels der Tetracyclinmethode gemessen. Die Wachstumsgeschwindigkeit variierte nur wenig innerhalb der einzelnen Altersgruppen. Die Geschwindigkeit war bei jungen Tieren am höchsten und nahm mit zunehmendem Alter beträchtlich ab. Männliche Ratten wuchsen schneller als weibliche. Diese Arbeit dient als Grundlage, um die experimentelle Beeinflussung des Längenwachstums der Ratte abschätzen zu können.
    Notes: Abstract The rate of normal growth in length from the proximal growth plate of the tibia in the Sprague-Dawley rat was measured between 20 and 100 days of age using the tetracycline method. The growth rate varied only slightly within different age groups. The rate was highest in young animals and decreased considerably with increasing age. Male rats grew faster than female. This study is intended to provide a base for an evaluation of experimental influence on the growth in length of the rat.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 9 (1972), S. 296-309 
    ISSN: 1432-0827
    Keywords: Osteoclasts ; Enzyme ; Parathyroid ; Microdissection ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une nouvelle méthode d'isolement d'ostéoclastes est mise au point pour des analyses biochimiques et de microscopie électronique. Pour isoler les cellules par microdissection, des empreintes d'os métaphysaire sont utilisées. Cette méthode, supérieure aux coupes d'os, permet une meilleure préservation cytologique et enzymatique et permet d'obtenir des cellules totales plus faciles à manipuler, avec des résultats plus reproductibles. Par analyse planimètrique de cellules isolées, colorées histochimiquement, il apparait que les ostéoclastes constituent plus de 90% de la masse de l'échantillon. Les concentrations de la phosphatase acide et de certaines enzymes, liées au nucléotide pyridinique, entrant dans le métabolisme de l'acide citrique, sont déterminées dans des échantillons d'ostéoclastes, pesant de 0,2 à 2,0 μg, isolés à partir de rats normaux et parathyroidectomisés. L'activité en aconitase, mesurée en direction de la transformation de citrate en isocitrate, est de 0,5–0,8 M/Kd/H, la plus faible des activités étudiées. Les activités en GDH et NADP-ICDH sont 5 à 10 fois supérieures que celle de l'aconitase, mais seulement un dixième à un tiers de celle de la phosphatase acide, de la déshydrogénase lactique ou malique.
    Abstract: Zusammenfassung Es wird eine neue Technik beschrieben, welche die Isolierung von Osteoklasten für biochemische und elektronenmikroskopische Untersuchungen ermöglicht. Als Ausgangsmaterial zur Zellisolierung wurden Abstriche von Metaphysenknochen benützt. Die Verwendung von Abstrichen bietet gegenüber Knochenschnitten wichtige Vorteile, wie z.B. eine bessere Erhaltung der cytologischen und enzymatischen Eigenschaften sowie die Gewinnung von unverletzten Zellen, welche leichter verarbeitet werden können und besser reproduzierbare Daten ergeben. Durch planimetrische Analyse der histochemisch gefärbten Ausstriche von isolierten Zellen konnte nachgewiesen werden, daß die Osteoklasten über 90% des gesamten Probenmaterials ausmachen. Die Mengen verschiedener Enzyme, welche an Pyridinnukleotid gebunden und am Citronensäuremetabolismus beteiligt sind, sowie der sauren Phosphatase wurden in Osteoklastenproben bestimmt, welche ein Gewicht von 0,2–2,0 μg hatten und aus Knochen von normalen und mit Parathyroidextrakten behandelten Ratten isoliert worden waren. Die Aktivität der Aconitase, welche in der Richtung von Citrat zu Isocitrat gemessen wurde, war mit 0,5–0,8 M/Kd/H die niedrigste aller untersuchten Aktivitäten. Die Aktivitäten der GDH und der NADP-ICDH waren 5–10mal höher als jene der Aconitase, entsprachen jedoch nur einem Zehntel bis einem Drittel derjenigen der sauren Phosphatase, der Laktat- oder der Malatdehydrogenase.
    Notes: Abstract A new method is described by which osteoclasts can be isolated for biochemical and electron microscopic analyses. As a source of cells for isolation by microdissection, imprints of metaphyseal bone were used. The use of imprints provides important advantages over bone sections, including a higher degree of cytologic and enzymatic preservation, and the delivery of whole cells which are more readily manipulated and which yield data that are more readily reproduced. By planimetric analysis of the histochemically-stained isolated cell samples, it was shown that osteoclasts represent over 90% of the sample mass. The levels of several of the pyridine nucleotide-linked enzymes involved in citric acid metabolism, as well as acid phosphatase, were determined in osteoclast samples weighing 0.2 to 2.0 μg isolated from normal and parathyroid-treated rats. Aconitase activity measured in the direction of citrate to isocitrate was 0.5–0.8 M/Kd/H, the lowest of the activities studied. The activities of GDH and NADP-ICDH were 5 to 10 times higher than that of aconitase but only a tenth to a third that of acid phosphatase, lactic or malic dehydrogenase.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 159 (1972), S. 87-98 
    ISSN: 1433-8580
    Keywords: Ultrastructure ; Small lymphocytes ; Throracic duct lymph ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die charakteristische Feinstruktur der durch Drainage des Ductus thoracicus des Menschen gewonnenen Lymphocyten wurde beschrieben, ihre Größe und Kern-Plasma-Relation durch planimetrische Verfahren ermittelt. Zwei morphologisch unterschiedliche Formen kleiner Lymphocyten konnten beschrieben werden: Zellen, die durch einen chromatinarmen Kern und relativ lockeres Cytoplasma gekennzeichnet sind, das zahlreiche Zellorganellen (Golgifeld, Centriolen, Mitochondrien und freie diffus verteilte Ribosomen) einschließt, sowie Zellen mit chromatinreichen Kern und dichtem Cytoplasma mit auffallend wenig Mitochondrien, jedoch relativ zahlreichen freien Ribosomen. Eine mögliche funktionelle Bedeutung dieser beiden morphologisch unterschiedlichen kleinen Lymphocyten wird diskutiert. Danach werden die Zellen der ersten Gruppe als differenzierte Zellformen, die der zweiten jedoch als immunologisch aktivere kleine Lymphocyten angesehen.
    Notes: Summary The ultrastructure of small lymphocytes of human thoracic duct lymph is described and planimetric studies of their size and nucleus-cytoplasm relationship are made. Two morphologically different small lymphocytes could be recognized; cells with a nucleus with little chromatin and a relatively light cytoplasm inclosing many organelles (Golgifield, Centriol, Mitochondria, Monoribosomes), cells with compact chromatin and dense cytoplasm including only a few mitochondria but many monoribosomes. The possible function of these morphological different small lymphocytes was discussed. The first group is a well differentiated cellform, the second one may contain more immonulogical active small lymphocytes.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Research in experimental medicine 159 (1972), S. 114-123 
    ISSN: 1433-8580
    Keywords: Scalds ; Local cooling ; Rat ; Quantity of leucocytes ; Verbrühung ; Lokale Kühlung ; Ratte ; Verhalten der Leukocyten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Untersuchungen an Ratten ergaben folgende Befunde: 1. Sofortige lokale Kühlung nach der Verbrühung beeinflußt bei der Ratte im untersuchten Zeitraum von 15 Tagen den Verlauf der Erkrankung gemessen am Parameter der Leukocytenzahl. 2. Die Kühlungszeit muß ausreichend lang sein. 3. Die Kühlung muß früh genug einsetzen, beim Versuchstier Ratte innerhalb 5 min nach Verbrühung. 4. Bei verspätetem Kühlungsbeginn läßt sich auch durch Verlängerung der Kühlungsdauer das Verhalten der Leukocytenzahl im Ablauf des Krankheitsgeschehens nach Verbrühung nicht beeinflussen.
    Notes: Summary Following results are obtained in experiments with rats: Immediate local cooling after scald had a significant influence on progress of “burn-disease”. Time for local cooling must be long enough, onset of local cooling early enough. It is not possible to restore the consequences of a late onset by prolongation of cooling.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 137 (1972), S. 301-316 
    ISSN: 1432-0568
    Keywords: Monoamines ; Brain ; Ontogeny ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The early ontogeny of the monoamine neuron systems in the rat brain has been analysed using Falck-Hillarp fluorescence histochemistry. Serial sagittal sections of embryos with a crown rump length between 7 and 13 mm, approximately corresponding to gestational days 12 to 15 were obtained from mothers treated with a monoamine oxidase inhibitor given in order to increase the monoamine levels of the embryos. 5-hydroxytryptamine (5-HT)-neurons made their first appearance in the 8 mm embryo, dopamine (DA)-neurons in the 9 mm embryo, and noradrenaline (NA)-neurons in the 11 mm embryo. Small, rounded, weakly fluorescent cell bodies forming sparse aggregations appeared first. Fluorescent processes of two types soon appeared. Short processes from the cell bodies were running perpendicular to the long axis of the brain stem within the cell groups, while long slender axon bundles could be traced ascending through the met- and mesencephalon and into the prosencephalon as well as descending in the myelencephalon andspinal cord. In the 12 mm embryo the primordial DA cell formation of the substantia nigra with its striatal projections, the 5-HT neuron formations of the caudal mesencephalon, met- and myelencephalon as well as the NA neurons of the met- and myelencephalon are relatively well developed. It is concluded that the monoamine-neurons develop mechanisms for synthesis and storage of amines at a very early stage during ontogeny, thus recapitulating the phylogeny of these old systems. Likewise, monoamine oxidase is present early. The presence of neurotransmitters specifying the different developing neurons long before development of their nerve terminal areas and therefore before the establishment of normal synaptic function may indicate a role of these substances during ontogeny other than transmission of nerve impulses.
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  • 10
    ISSN: 1432-0568
    Keywords: Rat ; Cold ; Pineal gland ; Synaptic vesicles ; Zinc iodide-osmium tetroxide (ZIO) reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In den synaptischen Bläschen der Nervenendigungen der Epiphyse von Ratten, welche 2 und 4 Tage einer Temperatur von −6° bis −8°C ausgesetzt worden waren, hat man eine signifikante Vermehrung des Zinkjodid-Osmiumtetroxyd (ZIO) reaktiven Materials festgestellt. Der durchschnittliche Durchmesser der ZIO-positiven synaptischen Vesiculae betrug bei den Kontrollratten 234 Å und bei den Ratten, welche 2 und 4 Tage unter der Kälte gelebt hatten, 380 Å, bzw. 379 Å. Die ZIO-Reaktion war bei den Kontrollratten in 49,3% der synaptischen Vesiculae positiv, nach zweitägiger Kälteeinwirkung waren 58,7% und nach viertägiger Kälteeinwirkung 72,1% der synaptischen Vesiculae ZIO-positiv. Auf Grund der vorliegenden Arbeit war es jedoch nicht möglich zu entscheiden, ob die Vermehrung des ZIO-reaktiven Materials mit einer gleichzeitigen Zunahme der biogenen Amine verbunden ist.
    Notes: Summary In the synaptic vesicles of pineal nerve endings of Wistar rats exposed for 2 and 4 days to a temperature of −6° to −8° C, a significant increase of the zinc iodide-osmium tetroxide (ZIO) reactive material was observed. The mean diameter of ZIO reactive synaptic vesicles of control rats was 234 Å; in rats exposed to cold for 2 and 4 days it was 380 Å, respectively 379 Å. In control rats the ZIO reaction was positive in 49,3% of the synaptic vesicles. The reactivity increased to 58,7% in rats exposed to cold for 2 days, and to 72,1% in rats exposed to cold for 4 days. However, the results of the present study do not permit to conclude if an increase of ZIO reactive material is accompanied by a simultaneuos increase of biogenic amines.
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  • 11
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    Electronic Resource
    Springer
    Anatomy and embryology 137 (1972), S. 1-29 
    ISSN: 1432-0568
    Keywords: Corticotropin-Releasing Factor ; Median eminence ; Rat ; Histology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der Zona externa infundibuli der normalen Ratte kommen geringe Mengen „Gomori-positiver” Granula vor. Nach bilateraler Adrenalektomie erfolgt eine Vermehrung der Granula, die sich durch Gabe von Hydrocortison einschränken oder verhindern läßt. Dieser Befund hat zu der Annahme geführt, daß die Granula das morphologische Äquivalent des Corticotropin-releasing factor (CRF) darstellen. Morphometrische Untersuchungen an 160 weiblichen Wistarratten zeigen, daß die Menge der nach bilateraler Adrenalektomie in der Zona externa infundibuli nachweisbaren „Gomori-positive” Granula von der postoperative Überlebensdauer abhängt. Die Granulamenge nimmt zunächst bis zum 14. Tag p.o. zu und fällt dann wieder ab. Substitution bilateral adrenalektomierter Ratten mit Hydrocortisonacetat-Kristallsuspension bewirkt eine dosisabhängige Verminderung der Granulamenge, wenn die Behandlung am Operationstag begonnen wird. Applikation von Hydrocortisonacetat-Kristallsuspension vom 14.–21. Tag p.o. führt dagegen zu einer gesteigerten Granulavermehrung. Auch bei stärkster Vermehrung sind die Granula stets nur im Infundibulum und nicht in anderen Bereichen des Hypothalamus nachweisbar. Sie besitzen bei bilateral adrenalektomierten Tieren ein charakteristisches Verteilungsmuster mit besonders hohen Konzentrationen in den paramedianen Abschnitten des rostralen Infundibulumdrittels. Aus der Art und Weise ihrer Verteilung ist zu vermuten, daß die Granula 2 Nervenfaserzügen angehören und ein Neurosekret darstellen. Nach den vorliegenden Untersuchungen besteht zwischen dem Verhalten der „Gomori-positiven” Granula in der Zona externa infundibuli und dem aus pharmakologischen Untersuchungen bekannten Verhalten des Corticotropin-releasing factor eine weitgehende Parallelität. Sie legt nahe, die Menge der Granula als Parameter der CRF-Aktivität zu verwenden.
    Notes: Summary In the zona externa infundibuli (outer layer of the median eminence) of the normal rat a minute number of “Gomori-positive” granules can be detected. Following bilateral adrenalectomy their number increases. This augmentation can be restricted or inhibited by administration of hydrocortisone, a finding, which has led to the assumption that the granules are the morphological equivalent of the corticotropin-releasing factor (CRF). Morphometrical studies on 160 female Wistar rats show that following bilateral adrenalectomy the quantity of “Gomori-positive” granules is dependent on the length of the post-operative survival period. Up to the 14th day p.o. the quantity of granules increases; from then on it diminishes. Substitution of bilaterally adrenalectomized rats with hydrocortisone acetate crystal suspension results in a dose-dependent decrease in the quantity of granules if treatment is begun on the day of operation. In contrast, administration of hydrocortisone acetate crystal suspension from the 14th to the 21st day p.o. results in increased augmentation of the granules. Even when maximum augmentation of the granules is reached, they are invariably found only in the infundibulum and not in other regions of the hypothalamus. In animals that have been subjected to bilateral adrenalectomy, the granules show a characteristic pattern of distribution, with particularly high concentrations in the paramedian parts of the rostral third of the infundibulum. The manner in which the granules are distributed suggests that they are a neurosecretory substance localized in two fibre tracts. The present study points to a close parallelism between the behaviour of the “Gomori-positive” granules in the zona externa infundibuli and that of the corticotropin-releasing factor as revealed by pharmacological investigations. It would seem that the quantity of granules can be used as a parameter of CRF activity.
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  • 12
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    Anatomy and embryology 137 (1972), S. 153-169 
    ISSN: 1432-0568
    Keywords: Embryology ; Epithelial autophagia ; Histocytochemistry ; Human palate ; Macrophages ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural and a histochemical study of the disintegration of the human fetal palatinal junctional epithelium was carried out. Special attention was focused both on the epithelium proper as well as on participation of the surrounding mesenchyma. Epithelial autophagia was noticed in the form of inclusion bodies with cellular remnants as well as general cellular disintegration. The disintegration was correlated to the cellular activity of acid phosphatase and AS-esterase. The differences between human and non-human material were recorded and discussed. In the surrounding mesenchyma, histiocytes (macrophages) were noticed participating in the epithelial disintegration, while ordinary mesenchymal cells seemed without importance. The study of activity of alkaline phosphatase reveals that the rapidly growing ossification center of the vomer was touching the superior aspect of the epithelial junctional seams, where the epithelial disintegration starts. Based upon the findings the following sequential steps of disintegration were discussed: 1) pressure from the outside (the vomer anlage), 2) epithelial autophagia and 3) heterophagia of epithelial remnants (invading histiocytes). The ultrastructure and histochemistry of the so-called epithelial pearls were described. The intercellular substance of the palatinal processes was found to consist of hyaluronic acid and of chondroitin-4- and/or-6-sulfate. The mutual ratio of the glycosaminoglucuronoglycans was discussed.
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  • 13
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    Anatomy and embryology 137 (1972), S. 106-113 
    ISSN: 1432-0568
    Keywords: Anterior pituitary ; Mouse ; Tissue culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Suitability of an ordinary incubation system for the culture of anterior pituitary tissues of mice was examined by electron microscopy. It was found that this system has many advantages over Trowell's standard technique for tissue culture and is particularly suitable for the short-term culture. In this system the pituitary tissue cultures were maintained well for at least two days in a chemically defined tissue culture medium (TC 199) without any additives. Addition of 20% calf serum to the medium extended the period to up to five days. Any attempts to prolong it further, however, failed because of a massive necrosis and a great loss of the histological integrity. In the cultured tissues there an enhancement of the LTH cells and a suppression of the other granulated types of cells were observed. The follicular cells were found to hypertrophy and to actively participate in phagocytosis of cell debris.
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  • 14
    ISSN: 1432-0568
    Keywords: Chick embryo ; Granular pneumocytes ; Granular inclusions ; Lamellar inclusions ; Ultrastructure ; Lung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Les inclusions lamellaires caractéristiques des cellules granuleuses de l'épithélium pulmonaire apparaissent chez le Poulet à 16 jours d'incubation. Elles dérivent d'inclusions granulaires que l'on peut déceler dans l'épithélium dès l'apparition de l'ébauche pulmonaire, à 21/2 jours d'incubation. Nous avons étudié l'évolution de ces deux types d'inclusions lorsque les ébauches pulmonaires sont transplantées sur des hôtes d'âge différent. Lorsque une ébauche pulmonaire jeune (21/2 à 3 jours) est greffée sur un hôte plus âgé (6 jours), l'évolution des inclusions granulaires est fortement stimulée et peut conduire à l'apparition d'organites présentant plusieurs des caractères des inclusions lamellaires. Lorsqu'au contraire, une ébauche pulmonaire est transplantée sur un hôte plus jeune (3 jours), deux cas peuvent se présenter: Ou bien l'épithélium ne contient pas encore d'inclusions lamellaires au moment de la transplantation (ébauche de 14 jours par exemple): le moment d'apparition de celles-ci est alors considérablement retardé et leur différenciation ne devient massive que lorsque les inclusions lamellaires apparaissent dans le poumon de l'hôte; Ou bien les inclusions lamellaires sont déjà différenciées (poumon de 18 jours par exemple): dans ce cas, leur différenciation se poursuit pendant toute la durée de la greffe. Lorsqu'une ébauche pulmonaire est transplantée sur un hôte plus âgé ou plus jeune, l'évolution ultrastructurale de l'épithelium est donc modifiée. Selon les cas, elle est stimulée ou, au contraire, freinée. Des facteurs présents dans le milieu intérieur de l'hôte influencent la différenciation des greffons. Ils pourraient également intervenir dans de développement normal des poumons.
    Notes: Summary The lamellar inclusions of the granular pneumocytes first appear in chick pulmonary epithelium at 16 days of incubation. They are derived from granular inclusions which can already be seen in the epithelium at the time when lung buds become distinct (at 21/2 days incubation). We have studied the fate of these two types of organelles after transplantation of embryonic lungs to hosts of a different age. When a young lung bud (21/2 to 3 days) is grafted into an older host (6 days), the development of the granular inclusions is strongly stimulated, and can lead to the appearance of organelles which exhibit several features characteristic of lamellar inclusions. When an embryonic lung is transplanted to a younger host, two situations can occur: Either the epithelium does not yet contain any lamellar inclusions at the time of transplantation (eg lung at 14 days); these appear after a considerable delay, and differentiate in large quantities only at the time of appearance of the inclusions in the host lungs. Or the lamellar inclusions are already differenciated (eg lung at 18 days), in which case, their differentiation continues in the host. Therefore, when a lung bud is transplanted into either a younger or older host, the ultrastructural development is modified. It is either stimulated or inhibited. Some factors, present in the host internal milieu, influence the differentiation of the grafts. These factors could also play a role in the normal development of the lungs.
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  • 15
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    Anatomy and embryology 138 (1972), S. 155-165 
    ISSN: 1432-0568
    Keywords: Cerebellum ; Neurogenesis ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Time of origin of various neuronal elements in the cerebellum of rat was established with the aid of tritiated-thymidine-autoradiography. The earliest nerve cells to form were the Purkinje cells, and they came into existence on days 15 and 16 of gestation. Interstitial nerve cells had their genesis on days 15, 16, 17 and 18, and the marginal cells on day 16 of the embryonic development. The Golgi cells were found to come into existence on days 17, 18 and 19 of gestation. On day 21 of gestation a number of small-medium-sized nerve cells, which were smaller than the Golgi cells but larger than the granule cells, were seen to come into existence. Finally, the earliest stock of granule, basket and stellate cells, primarily in the nodulus, flocculus and para-flocculus, were observed to have been formed on the day 21 of embryogenesis.
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  • 16
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    Acta neuropathologica 21 (1972), S. 253-257 
    ISSN: 1432-0533
    Keywords: Haemangiopericytoma, Cerebral-Secondary ; Histology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A secondary haemangiopericytoma of the cerebral hemisphere in a woman of 23 is described. It is formed of cells arranged in masses around proliferating blood capillaries, and also in rosette patterns. The tumour cells are separated from the capillary endothelial cells by thick collars of basement membrane in abnormal amounts. The histology of the primary tumour of the sacrum, and of the secondary tumours in the lungs and nervous system, are similar. A metastatic haemangiopericytoma of the central nervous system appears not to have been previously reported.
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  • 17
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    Acta neuropathologica 21 (1972), S. 109-116 
    ISSN: 1432-0533
    Keywords: Infantile Neuro-Axonal Dystrophy ; Motor End Plates ; Nerve ; Spheroïds ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report the ultrastructure of neuromuscular biopsies in three cases of infantile neuro-axonal dystrophy. The presence of spheroïds in peripheral and intramuscular nerves, but also in the motor end plates allows the diagnostic of this disease, without doing cerebral biopsy.
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  • 18
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    Acta neuropathologica 22 (1972), S. 269-271 
    ISSN: 1432-0533
    Keywords: l-DOPA ; Neoplasm, Striatal ; Motor Behavior ; Rat ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After administration ofl-DOPA to a rat with a unilateral striatal neoplasm of the nucleus caudatus-putamen, postural asymmetries and rotating behavior were observed. These observations are discussed in relation to the activity of catecholamines within the central nervous system.
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  • 19
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    Acta neuropathologica 20 (1972), S. 248-257 
    ISSN: 1432-0533
    Keywords: Experimental CNS Tumours ; N-Nitrosomethylurea ; Ethylnitrosourea ; Cell Culture ; Clonal Growth ; Aggregation Pattern ; Transplantation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two sarcomas, one neurosarcoma and one polymorphous tumour of uncertain classification of the central nervous system of the rat induced by N-nitrosomethylurea or ethylnitrosourea were the source of 14 clones. The cytomorphology and the aggregation pattern of the clonesin vitro are described. The malignancy and histology were checked by homologous transplantation. All the clones formed sarcoma-like structuresin vivo, but it was difficult to decide whether these neoplasias were real sarcomas or very dedifferentiated glial tumours. The differences in cytology observedin vitro were greater than the histological differencesin vivo.
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  • 20
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    Acta neuropathologica 21 (1972), S. 68-75 
    ISSN: 1432-0533
    Keywords: Myelinated Nerve ; Venom ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of right sciatic nerves of Swiss white mice was studied after being exposed to a venom solution ofAgkistrodon contortrix laticinctus (broad-banded copperhead) and to 0.9% NaCl solutions for periods of 1, 2 or 3 h. There was some “Wallerian-like” degeneration in all groups of nerves in the experiment. Additional neuropathological changes were noted in the nerves exposed to venom solutions. The connective tissue was affected most severely, while the basal lamina was unaffected. Schwann cells were vacuolated, and in the most extreme case, a type of myelin splitting occurred which was considered as a “demyelinative” effect. The results were compared to those of Martin and Rosenberg (1968) [15] on studies of the giant squid axon. References to additional fine structural studies of various other neuropathies were given.
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  • 21
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    Acta neuropathologica 21 (1972), S. 239-252 
    ISSN: 1432-0533
    Keywords: Ultrastructure ; Myotendon ; Zebra-Bodies (ladder-like structure) ; Rods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of the adult and foetal human myotendon is described. At the myotendon the muscle fibre is surrounded by plasma and basement membranes which are never penetrated by the adjacent collagen fibrils of the tendon. Increased thickness and electron density of the plasma membrane and the myofilaments which merge with it occur at the myotendon and this electron dense zone corresponds to the terminal Z-line of the final sarcomere of the myofibril. In the adult the muscle fibre near the myotendon may contain nemaline rods and zebra-bodies. The tendon in the foetus shows much more activity of the fibroblasts than in the normal adult. The collagen fibrils of the early foetus are thinner in diameter than at later stages of development. The union of the tendon with cartilage is illustrated.
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  • 22
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    Calcified tissue international 9 (1972), S. 238-242 
    ISSN: 1432-0827
    Keywords: Dentine ; Ultrastructure ; Tubule ; Tooth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'étude ultrastructurale de la dentine humaine périphérique, de couronnes dentaires de sujets âgés de 11 à 75 ans, a montré trois aspects principaux du contenu des canalicules en coupe transversale. Il s'agit de canalicules apparemment vides, de canalicules contenant un matériel organique annulaire et, enfin, de canalicules totalement remplis d'un matériel organique d'aspect granulaire ou hyalin. Aucune terminaison nerveuse n'est visible à ce niveau.
    Abstract: Zusammenfassung Die ultrastrukturelle Untersuchung von peripherem menschlichem Zahnkronendentin bei Patienten im Alter von 11–75 Jahren hat drei Hauptaspekte des Inhaltes der Dentintubuli gezeigt. Sie bestehen bei transversalen Schnitten aus toten Gängen sowie beim Lumen der Tubuli entweder aus ringförmigen oder ganzausfüllenden Ablagerungen. Im äußeren Dentin wurden keine Nervenendigungen beobachtet.
    Notes: Abstract An ultrastructural study of peripheral human coronal dentin in patients aged 11 to 75 years, has shown main aspects of the dentinal tubular content. In transverse sections, they consist of dead tracts and annular or solid content to the tubular lumen. No nerve endings were observed in the outer dentin.
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  • 23
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    Naunyn-Schmiedeberg's archives of pharmacology 272 (1972), S. 417-436 
    ISSN: 1432-1912
    Keywords: Intestinal Blood Flow ; Instestinal Absorption ; Tritiated Water-Solvent Drag ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Jejunal loops of anaesthetized rats were perfused with hypo-, iso-, and hypertonic buffered solutions containing tritiated water. The blood flow, the disapperance rate (from the intestinal lumen), and the appearance rate (in the intestinal venous blood) were determined simultaneously. 2. A decrease of the blood flow from about 1.7 to 0.2 ml min−1g−1 wet tissue weight diminished the appearance and disappearance rate of tritiated water. An increase of the blood flow caused the reversed results. The appearance rate was almost completely determined by the blood flow indicating that the intestinal absorption of tritiated water is blood flow limited. Therefore the absorption rate of tritiated water characterizes badly the diffusive water permeability of the intestinal epithelium. 3. A water net flux directed towards the blood accelerated and towards the intestinal lumen retarded the intestinal absorption of tritiated water at low, intermediate, and high blood flow values. 4. The data were analysed by a modified four-compartment-model considering the variation of blood flow and water net flux. The water net flux influences the absorption of tritiated water during the penetration through the epithelium by solvent drag (sieving coefficient 1-σ=1.54±0.19) as well as by changing the blood flow rate through capillaries near the epithelium.
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  • 24
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    Psychopharmacology 26 (1972), S. 195-200 
    ISSN: 1432-2072
    Keywords: Forced Motility ; Motor Activity ; Brain Noradrenaline and 5-Hydroxytryptamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The levels of 5-HT and 5-HIAA in the rat brain were measured after 1, 6, 24 and 36 h of forced motility in a treadwheel. The results showed that 5-HT metabolism had already increased in the forebrain after 1 h of exercise but later also increased in the brain stem, especially in the mesencephalon-pons-medulla regions. These changes had almost entirely disappeared after 50 min of rest. The NA levels with and without monoamine oxidase inhibitor were measured in animals after 36 h of forced motility. The results indicated an increase in NA metabolism in the brain stem.
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  • 25
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    Psychopharmacology 26 (1972), S. 317-320 
    ISSN: 1432-2072
    Keywords: Oxazepam ; Conflict Behavior ; Rat ; Maze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were tested in a Lashley III maze, the floor of which was heated. The animals had to learn to negotiate it in order to gain access to the unheated goal box. In the early period of training the animals were able to find the goal box rapidly and without error. Their performance then deteriorated, in a particular way which strongly evoked a conflict behavior. This deterioration in performance was progressively reduced by oxazepam administration (8 mg/kg/day).
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  • 26
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    Psychopharmacology 26 (1972), S. 347-360 
    ISSN: 1432-2072
    Keywords: Chronic Nicotine ; Attention Task ; Arousal ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male, Holtzman rats were trained extensively on an attention task which required them to respond with a single lever-press to a very short, variably presented stimulus for food reinforcement, but which also required them to inhibit inappropriate responses. After performance had stabilized, two groups were treated with either nicotine base (100 Μg/kg, s.c., t.i.d.) or saline for 4 weeks. The groups were crossed-over so that the first received saline and the second nicotine for an additional 4 weeks. A 3-week saline recovery period followed. Rats were tested on the attention task daily through all periods. Analysis of the data indicated that independent of the treatment-order, rats performed more efficiently under nicotine treatment than under saline conditions. The improvement in performance was most notable in the reduction of inappropriate responding during chronic nicotine treatment. The significance of the behavioral changes in relation to proposed nicotine-induced neurophysiological changes and the two-arousal hypothesis are discussed.
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  • 27
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    Psychopharmacology 24 (1972), S. 449-455 
    ISSN: 1432-2072
    Keywords: Avoidance and Acquisition ; Methamphetamine ; Discrimination Learning ; CNS Stimulants ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Avoidance responses, extra responses (on avoidance lever) and wrong lever responses were measured in naive rats acquiring a discriminated avoidance in a 2 lever Skinner box, 30 min after methamphetamine (0.25, 0.5 and 1.0 mg/kg). The smallest dose was ineffective; 0.5 and 1.0 mg/kg significantly increased the number of avoidance responses. This increase was not associated with a significant increase in the two other responses studied. The progressive increase (from the first to second part of the acquisition session) in avoidance responses was not accompanied by a parallel increase in the other responses. The position discrimination and the discrimination of the presence or absence of the conditioned stimulus was observed to be better in the drug groups.
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  • 28
    ISSN: 1432-2072
    Keywords: Agressive Behaviour ; Apomorphine ; Testosterone ; Testes ; Hypophysis ; Adrenal Glands ; Thyroid ; Castration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The weights of testes, prostates, adrenals, thymus and the pituitary of rats with apomorphine induced aggressiveness did not differ from those without aggressiveness. Postpubertal castration, adrenalectomy or thyroidectomy did not reduce the apomorphine induced aggressive behaviour, but a considerable reduction was found after hypophysectomy. Prepubertal castration significantly reduced, but did not completely abolish the proportion of aggressive rats, especially when castration was performed on the 5th day. Prolonged treatment of male, female and castrated rats with high doses of testosterone from the time of weaning increased the proportion of aggressive animals. Less intensive treatment and treatment of adult rats were ineffective.
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  • 29
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    Psychopharmacology 25 (1972), S. 218-228 
    ISSN: 1432-2072
    Keywords: Fighting ; Delta-9-Tetrahydrocannabinol ; Chlordiazepoxide ; Fixed-Interval ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The frequency with which electric shock to the feet elicited fighting in five pairs of albino rats was not altered significantly by intraperitoneal injections of delta-9-tetrahydrocannabinol (THC) in doses ranging from 0.064–6.4 mg/kg, although chlordiazepoxide reduced the frequency of such fighting in a dose-related manner. This finding held true despite manipulations of THC vehicle, injection-test interval, and the previous drug experience of the subjects. In contrast, doses of 4.0 mg/kg produced a striking reduction in lever-pressing maintained by an FI 60″ schedule of food reinforcement.
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  • 30
    ISSN: 1432-2013
    Keywords: Diphosphate ; Rat ; Vitamin D Metabolism ; Intestinal Calcium ; Absorption ; Bone Mineralization ; Renal Functions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The metabolism and the organ distribution of double labelled vitamin D3 (1,2-3H-4-14C-cholecalciferol) has been studied in rats in which the bone mineralization and the intestinal calcium absorption have been inhibited by a large pose (10 mg P/kg s.c. for 7–14 days) of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP). The most striking difference found was a reduced accumulation of radioactive cholecalciferol and its metabolites in the kidney of EHDP-treated rats. It is unlikely that this effect was due to an unspecific alteration of the functional renal tissue since blood urea, glomerular filtration rate and renal plasm a flow remained unaltered by this dose of EHDP. The EHDP-treated rats were able to form the metabolite eluted with peak IV of the silicic acid chromatographic system, that is 25-hydroxycholecalciferol. In these vitamin D repleted rats fed a high calcium diet, the tritium deficient metabolite eluted with peak V (1,25-dihydroxycholecalciferol) was only found in the intestinal mucosa of both control and EHDP groups three days after the injection of radioactive cholecalciferol, and this in a very small amount. Therefore no definitive conclusion can be drawn as to a possible interference of EHDP treatment on the production of 1,25-dihydroxycholecalciferol. The change in the renal metabolism of vitamin D in rats treated with a rachitogenic dose of EHDP may be caused by the modifications of the calcium metabolism brought about by the diphosphonate. Its relation, if any, with the decreased calcium absorption remains to be established.
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  • 31
    ISSN: 1432-2013
    Keywords: Cardiac Output ; Blood O2 Dissociation Curve ; High Altitude ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rats adapted to a simulated altitude of 3500 m cardiac output measured at hypoxia by the direct Fick principle was significantly lower than in the control animals (mean values 54.3 ml/min and 69.8 ml/min, resp.). The decrease of cardiac output was accompanied by an increase of arterio-venous O2 difference and a decrease of stroke volume in the adapted rats. It is suggested that the decrease of cardiac output might be related to the increase of hematocrit. The adapted rats also showed higher arterial and mixed-venous O2 content (both at hypoxia) and increased O2 capacity. Arterial O2 saturation of the animals previously exposed to simulated high altitude hypoxia was significantly higher (67.3% as against 61.2% in the controls). The standard O2 dissociation curve showed lower oxygen affinity in the blood of the adapted animals but no physiological advantage concerning the transport of O2 to the tissues was found. In another group of animals the Bohr factor was estimated and no difference was found between rat and human blood.
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  • 32
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    Pflügers Archiv 335 (1972), S. 198-212 
    ISSN: 1432-2013
    Keywords: Intestinal Absorption ; Medium Chain Fatty Acids ; Kinetics ; Active Transport ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The transport of14C-octanoate by rat small intestine was determined in vitro by a modification of the method of Semenza and Mühlhaupt, and in vivo by using isolated segments or a perfusion technique in conscious rats (Haberichet al., 1968). 2. The absorption capacity of14C-octanoate in the distal ileum was significantly lower than in the proximal jejunum. 3. 14C-octanoate injected into a jejunal segment appeared rapidly in portal venous blood reaching its maximal concentration 4 min after the injection. 4. The transport of octanoate showed a saturation effect with increasing concentrations after an incubation of 4 min. However, with constant concentrations of octanoate in the medium, the transport rate was constant for 8–10 min. A similar saturation effect was also demonstrated in vivo. Values for maximal absorption rate (V max) and the half-saturation constant (K m), calculated from the Lineweaver-Burk plot, were 1.0 μMol/min and 17.7 mM, respectively. 5. Accumulation of octanoate in tissue water was demonstrated. For example, after incubation for 40 min in a medium concentration of 0.1 mM, the tissue/ medium ratio was 2.75:1. 6. Cyanide (2×10−4 M) markedly diminished the absorption rate of octanoate. 7. The absorption of octanoate was competitively inhibited by caproic acid (C6) in vitro. The inhibition constant (K i), calculated from the Dixon plot, was 47 mM. 8. Simultaneous administration of glucose and octanoate in vivo did not affect the absorption rate of the fatty acid. 9. These results suggest that the intestinal absorption of octanoate is an energy-dependant active process.
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  • 33
    ISSN: 1432-2013
    Keywords: Pulmonary Diffusing Capacity ; Alveolar-arterial O2 Pressure Difference ; High Altitude ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Steady-state pulmonary diffusing capacity for CO and alveolar-arterial O2 pressure differences were measured at hypoxia in growing rats adapted to a simulated altitude of 3500 m. The pulmonary diffusing capacity was significantly higher and the alveolar-arterial gradients were significantly lower in the adapted animals as compared with the controls exposed to hypoxia for the first time. The increased diffusing capacity could be explained entirely by the increase of blood O2 and CO capacity whereas the decrease of gradients might be explained by the increase of blood O2 capacity together with an increase of the arterio-venous O2 difference.
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  • 34
    ISSN: 1432-2013
    Keywords: Cardiac Hypertrophy ; Diffusion Distance ; High Altitude ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In growing rats adapted to a simulated altitude of 3500 m for about 4 weeks and in their controls the evolution of cardiac ventricular weight was followed. The increase of total ventricular weight found in the adapted animals can be attributed exclusively to the increase of right ventricular weight. In other adapted and control animals cardiac capillary densities, muscle fiber diameter and external capillary radius were estimated and fiber—capillary ratio and diffusion distance were calculated. There was an increase of capillary density together with a decrease of muscle fiber density, fiber-capillary ratio and diffusion distance in the right but not in the left ventricle of the adapted rats. The muscle fiber diameters, however, were larger in both heart ventricles of the rats exposed to a simulated high altitude, especially in the right ventricle. This indicates that true hypertrophy of the muscle fibers is mainly responsible for the increase of right ventricular weight. In the left ventricle, however, a hypertrophy of the muscle fibers together with a decrease of stroma components is demonstrated. The physiological importance of the shorter diffusion distance in the right ventricle of the high altitude adapted rats is discussed and it is suggested that the shorter diffusion distance may help to keep the tissue O2 partial pressure above the critical value, mainly also in extreme situations with high myocardial O2 consumption.
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  • 35
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    Experimental brain research 15 (1972), S. 29-38 
    ISSN: 1432-1106
    Keywords: Ventromedial hypothalamus ; Single units ; Spontaneous and stimulated activity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The relationship between mean firing rate and activity pattern was studied in 177 neurons in the ventromedial hypothalamus of rats immobilized by Remyolan. Stationary epochs of spontaneous or stimulated activity containing at least 512 interspike intervals were analyzed with the LINC computer. The most frequently encountered interval histograms (IHs) were of the exponential (35%) or gamma 2 (25%) type. The IH shape remained unchanged even if the average firing rate was varied over a wide range (from 20/sec to 2/sec) by polarization through the recording microelectrode (2–5 nA, 1–10 min) or by intracarotid injection of glucose (0.1 ml, 10–25%). The coefficient of variation (CV = SD/ mean interval) was 1.03 for the spontaneous and 0.90 or 0.95 for the activity influenced by polarization or glucose, respectively. Since according to other studies sensory stimulation decreases CV by reorganization of the synaptic input, it is suggested that polarization and glucose affect predominantly the postsynaptic elements without significantly changing the presynaptic activity pattern.
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  • 36
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    Archives of toxicology 28 (1972), S. 39-45 
    ISSN: 1432-0738
    Keywords: Ferrihexacyanoferrate (II) ; Rat ; Thallium ; Toxicity ; Metabolism ; Ferrihexacyanoferrat(II) ; Ratte ; Thllium ; Toxicität ; Stoffwechsel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Verabfolgung einer 2% igen kolloidalen Lösung von Ferrihexacyanoferrat (II) (FHCF) als Trinkwasser erhöht bei der Ratte die Ausscheidungsrate von intravenös injiziertem Tl2SO4 (mit 204Tl markiert) aus Leber, Nieren und Muskulatur auf das 2,8fache. Dieser Effekt ist zeitunabhängig. Die LD 50/30 d von intravenös injiziertem Tl2SO4 wird durch FHCF-Behandlung um das 2,3fache erhöht. Für diesen Schutzeffekt ist allerdings nur das während der ersten 24 Std verabfolgte FHCF verantwortlich. Diese Befunde weisen darauf hin, daß die Schäden bei der akuten Tl-Intoxikation sehr schnell irreversibel werden.
    Notes: Abstract The administration of a 2% colloidal solution of ferrihexacyano ferrate (II) (FHCF) as drinking water increases in the rat the excretion of intravenously injected Tl2SO4 (labelled by 204Tl) from liver, kidneys and muscles by a factor of 2.8. This effect is independant of time. FHCF-treatment increases the LD 50/30 d of intravenously injected Tl2SO4 by a factor of 2.3. This protection, however, is provided by FHCF only if administered during the first 24 hours. These findings suggest that the damage resulting from acute Tl-intoxication quickly becomes irreversible.
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  • 37
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    Archives of toxicology 30 (1972), S. 29-38 
    ISSN: 1432-0738
    Keywords: Dichlorvos ; Teratology ; Inhalation ; Rat ; Rabbit ; Dichlorvos ; Teratologie ; Inhalation ; Ratte ; Kaninchen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Kaninchen und Ratten wurde die teratogene Wirkung von inhaliertem Dichlorvos untersucht. Im Versuch waren primipare Kaninchenweibchen der Rasse “Dutch” mit einem Anfangsgewicht von 2 bis 3 kg und primipare Rattenweibchen vom Stamm “Carworth Farm E“ mit einem Anfangsgewicht von 200 bis 300 g. Die Tiere wurden während der gesamten Trächtigkeit folgenden Konzentrationen in der Atemluft ausgesetzt: 0,25, 1,25 und 6,25 μg Dichlorvos pro Liter Luft. Ein zusätzliches Experiment am Kaninchen wurde mit 2 und 4 μg Dichlorvos pro Liter Luft durchgeführt. Die Behandlung wirkte weder beim Kaninchen noch bei der Ratte teratogen. Selbst Konzentrationen, die für die Kaninchen tödlich waren, und die eine deutliche Cholinesterasehemmung in Plasma, Erythrocyten und Gehirn der Ratten und Kaninchen hervorriefen, wurden ohne Schädigung für die Feten vertragen.
    Notes: Abstract The teratogenic potential of inhaled dichlorvos vapour for rabbits and rats was investigated on the offspring of primiparous female Dutch rabbits weighing 2 to 3 kg and primiparous female Carworth E strain rats weighing 200 to 300 g. The animals were exposed throughout pregnancy at concentrations of 0.25, 1.25 and 6.25 μg dichlorvos per litre of air. In an additional experiment pregnant rabbits were exposed to concentrations of 2 and 4 μg dichlorvos per litre of air. The results gave no indication that dichlorvos vapour is teratogenic in rabbits or rats even at exposure concentrations resulting in maternal deaths in rabbits, and causing depression of plasma, erythrocyte and brain cholinesterase activities in pregnant animals of both species.
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  • 38
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    Archives of toxicology 29 (1972), S. 39-49 
    ISSN: 1432-0738
    Keywords: Mouse ; Rat ; Brain ; Light-Dark-Programming ; Circadian ; Toxicity Rhythms ; Acetylcholine ; Pilocarpine ; Oxotremorine ; Carbachol ; Physostigmine ; Neostigmine ; Atropine ; Scopolamine ; Atropine Methyl Nitrate ; Maus ; Ratten ; Gehirn ; Beleuchtungsprogramm ; Circadianer Toxicitätsrhythmus ; Acetylcholin ; Piloearpin ; Oxotremorin ; Carbachol ; Physostigmin ; Neostigmin ; Atropin ; Scopolamin ; Atropin-methylnitrat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Nach Adaptation an ein Licht-Dunkelprogramm (8.00 bis 20.00 Licht, 20.00 bis 8.00 Dunkelheit) wurde der Acetylcholingehalt (ACh) im Mittelhirn und N. caudatus von Ratten sowie im Gesamthirn von Mäusen bestimmt. Die höchsten ACh-Konzentrationen wurden bei Ratten um 24.00 gefunden; die höchsten ACh-Werte bei der Maus waren nicht signifikant von den Konzentrationen um 24.00 und 12.00 verschieden. Signifikante ACh-Minima traten im Mittelhirn der Ratte um 12.00, im N. caudatus sowie im Mäusegehirn um 18.00 Uhr auf. Während der Dunkelperiode wurde die größte Toxicität gegenüber i.v. bzw. i.p. injiziertem ACh bei Mäusen gefunden. Ähnliche zeitliche Unterschiede ergaben sich für Neostigmin, Pilocarpin und Oxytremorin. Die Toxicität von Carbachol zeigte Maxima bei 12.00 und 24.00. Für Physostigmin, einen CholinesteraseHemmstoff mit einem tertiären Stickstoff, lagen sowohl die Toxicitätsmaxima als auch die Toxicitätsminima in der Dunkelperiode. Die rhythmische Schwankung der Toxicität von i.p. verabfolgtem Atropin verhielt sich umgekehrt wie die der Cholinomimetica (außer Carbachol). Auch nach i.v. Applikation von Scopolamin und N-Methylatropin war ein entsprechender rhythmischer Einfluß auf die Toxicität nachweisbar. Die Vorbehandlung mit N-Methylatropin schwächte die Toxicität zwar ab, der Toxicitätsrhythmus gegenüber ACh und Physostigmin war aber nicht verändert. Die Toxicität von Cholinomimetica zeigt ein Maximum während der höchsten ACh-Konzentrationen im Gehirn und der höchsten Stoffwechselaktivität. Bei den anticholinergen Substanzen zeigte sich ein umgekehrtes Verhältnis. Die Beziehungen zum zentralen ACh-Gehalt sind unklar.
    Notes: Abstract Acetylcholine (ACh) levels were determined in rat midbrain and caudate nucleus and mouse whole brain in mature animals adapted 3 weeks to a programmed lighting schedule (08:00 to 20:00 h light; 20:00 to 08:00 dark). Peak ACh levels in the rat occurred at 24:00 h; in the mouse the peak at 06:00 h did not differ significantly from values obtained at 24:00 and 12:00 h. Significant trough values occurred at 12:00 h in rat midbrain and at 18:00h in rat caudate nucleus and mouse brain. In mice toxicity of I.V. and I.P. administered ACh is maximal during the dark. Neostigmine, pilocarpine and oxotremorine have toxicity patterns similar to ACh. Carbachol toxicity peaked at 12:00 and 24:00 h. With physostigmine, a tertiary anticholinesterase, peak and trough occurred during the dark. The atropine (I.P.) toxicity rhythm is a mirror image of the cholinomimetic rhythm (except for carbachol). I.V. scopolamine and atropine methyl nitrate patterns resemble atropine's but are less clear-cut. Atropine methyl nitrate pretreatment reduced ACh and physostigmine toxicity but did not alter the overall pattern. Cholinomimetic toxicity and brain ACh patterns are similar, peaking when metabolic activity is maximal. An inverse relationship holds for the anticholinergic drugs. The relationship to central ACh is uncertain.
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  • 39
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    Archives of toxicology 30 (1972), S. 9-18 
    ISSN: 1432-0738
    Keywords: 2,2-Dichlorvinyl Dimethyl Phosphate ; Dichlorvos ; Vapona ; Metabolism ; Man ; Rat ; Mouse ; Hamster ; 2,2-Dichlorvinyl-dimethylphosphat ; Dichlorvos ; Vapona® ; Stoffwechsel ; Mensch ; Ratte ; Maus ; Hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Mäusen und Hamstern wurde die Exkretion und Retention der Radioaktivität nach Fütterung mit [1-14C-Vinyl]-Dichlorvos bestimmt. Außerdem wurde beim Menschen die Exkretion und Exhalation gemessen und die erhaltenen Werte mit den tierexperimentellen Daten von Rattenversuchen verglichen. Die Ergebnisse zeigen einen schnellen Stoffwechsel von Dichlorvos bei allen vier untersuchten Species. Die Dealkylierung zu Desmethyldichlorvos spielt bei der Biotransformation eine untergeordnete Rolle. Eine gewisse Ausnahme zeigen die Mäuse, bei denen 18,5 % der zugeführten Radioaktivität als Desmethyldichlorvos aufgefunden werden konnte. Bei allen Species kam es zu einer hydrolytischen Spaltung zu Dichloracetaldehyd, der weiter zu Dichloraetbanol reduziert wird. Der weitere Weg führt über die Ausscheidung als Glucuronid mit dem Harn. Ein Teil wird dechloriert und das14C-Atom als14CO2 oder14C-Hippursäure im Harn ausgeschieden. Im menschlichen Harn konnte Dichloraethanol nach Inkubation mitβ-Glucuronidase nachgewiesen werden, wenn hohe Dichlorvoskonzentrationen (38 μg/l) eingeatmet wurden. Auf dieser Basis könnte eine Überwachungsmethode gegen die Inhalation von zu hohen Dichlorvoskonzentrationen ausgearbeitet werden.
    Notes: Abstract The routes of excretion and retention of radioactivity following the ingestion of [1-14C-vinyl]dichlorvos by mice and hamsters have been determined. The excretion of radioactivity in urine and exhaled air of man has also been measured. The data have been compared with those for rats. The results indicate that metabolism is rapid in the four species. Dealkylation to desmethyldichlorvos is a minor route of biotransformation, except in the mouse, where desmethyldichlorvos constitutes at least 18.5 % of the administered radioactivity. Hydrolytic metabolism of dichlorvos occurs in all species and leads presumably to dichloroacetaldehyde which is further metabolized by (i) reduction to dichloroethanol and excretion in the urine as the glucuronide and (ii) dechlorination followed by incorporation of the carbon atoms into endogenous biosyntheses and excretion as [14C]carbon dioxide and [14C]hippuric acid in the urine. Dichloroethanol can be detected inβ-glucuronidase-treated urine after exposure of a human subject to high air concentrations (38 μg/l) of non-radioactive dichlorvos. This may form the basis of a method of monitoring the exposure of humans to high concentrations of dichlorvos.
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  • 40
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    Journal of cancer research and clinical oncology 77 (1972), S. 279-291 
    ISSN: 1432-1335
    Keywords: Lung mouse tumors ; Chemical carcinogen ; Ultrastructure ; Pneumocyte II ; Crystalline inclusions ; Interstitial fibrosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The pulmonary tumours induced in Swiss mice by NMUR seem to be constituted for the most part by cells closely related to the granular pneumocytes (pneumocytes II ou B). Other rarer cells, of epithelial bronchiolar aspect, may take part in the proliferation. The ultrastructural study of tumoral cells suggest that their secretory functions are disturbed. The origin of the crystalline intratumoral structures is discussed, as well as their possible relationship with the production of surfactant. The peritumoral areas are characterized by a dense interstitial flbrosis in which the collagen fibers are associated with an elastoid substance.
    Notes: Resumé Les tumeurs pulmonaires induites chez la souris swiss par le NMUR apparaissent essentiellement constituées de cellules apparentées aux pneumocytes granuleux (pneumocytes II ou B). D'autres cellules plus rares, de morphologie épithéliale bronchiolaire peuvent participer á la prolifération. L'étude ultrastructurale des cellules tumorales suggère que leurs fonctions secrétoires sont perturbées. Le mode de formation des structures cristallins intratumorales est discuté, ainsi que leur rapport éventuel avec la production du surfactant. Les territoires péri-tumoraux sont caractérisés par une fibrose interstitielle dense où les fibres de collagène sont associées à uns substance élastoïde.
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  • 41
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    Pflügers Archiv 331 (1972), S. 357-364 
    ISSN: 1432-2013
    Keywords: Thoracic Aorta ; Complex Dynamic Young's Modulus ; Age ; Serum Lipids ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 2 groups of male albino rats (wistar-strain), 6 months and 18 months of age, dynamic Young's moduli in longitudinal direction were measured, at 5 different frequencies between 1 and 5 Hz. Each group consisted of 10 animals. Measurements were made at the natural length and at 1.2 times this length. From each animal several serum lipids were determined. It was found that: 1. measured at the natural length and 1.2 times this length, no significant difference of dynamic Young's moduli between both age groups could be demonstrated 2. concerning the dynamic Young's moduli there is significant interaction between stretch level and age 3. retraction was significantly smaller in the old rats than in the young ones 4. the old animals had a significantly higher serum lipid content than the young rats 5. no correlation between serum lipids and Young's moduli could be demonstrated.
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  • 42
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    Pflügers Archiv 337 (1972), S. 71-79 
    ISSN: 1432-2013
    Keywords: Rat ; Hypothalamus ; Prolactin ; LH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Plasma levels of prolactin and LH were measured by radioimmunoassay following electrochemical stimulation of the medial preoptic area (MPO) or the arcuate nucleus (Arc.N.) in pentobarbital anesthetized proestrous rats. Differences in the secretion pattern of prolactin and LH were observed when stimulated by means of acutely or chronically implanted electrodes. Acute implantation and stimulation of the MPO resulted in no change in serum prolactin levels, whereas stimulation by means of chronically implanted electrodes evoked a marked increase in serum prolactin. The general observation was that electrostimulation in the acute experiments causes a less sharp but more prolonged prolactin and LH release from pituitary than stimulation through chronically implanted electrodes.
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  • 43
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    Pflügers Archiv 334 (1972), S. 293-302 
    ISSN: 1432-2013
    Keywords: Lactate Turnover ; l-Lactate14C (U) ; Hypoxaemia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Lactate turnover was measured in 24 anesthetized rats using14C-U-(l) Lactate with the priming dose-infusion technique. 2. 14C Lactate in blood was determined with a specific radio-enzymatic micromethod. 3. Lactate turnover increases with blood lactate concentration in the range 0.5 to 3 mM. In a steady state system this relationship means that a new equilibrium may be achieved at a higher pool level, between lactate production and utilization. 4. Comparing available data in four mammalian species lactate turnover at normal lactate levels was found to be approximately constant when computed on a body surface unit basis.
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  • 44
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    Psychopharmacology 23 (1972), S. 171-179 
    ISSN: 1432-2072
    Keywords: Reserpine ; Neonatal Treatment ; Sexual Behaviour ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To investigate whether reserpine given in the critical period of sexual differentiation of the rat brain affects adult sexual behaviour, female and male rats were given a single injection of reserpine on the fourth day after birth, and their sexual behaviour was tested at maturity. In the 11 consecutive daily tests for spontaneous sexual behaviour the reserpine treated female animals showed fewer regular behavioural and vaginal oestrous cycles than the control animals. 19 % of the reserpinized and none of the control animals had prolonged oestrous behaviour without a coincident prolonged vaginal cycle. The reseptivity quotients of the reserpine treated animals were reduced. In the tests for hormone induced sexual behaviour after ovariectomy no statistically significant differences between the number of animals responding or between the receptivity quotients occurred. The tests for spontaneous sexual behaviour in males showed that the reserpinized animals needed fewer intromissions to ejaculate than the controls. The significance of these findings is discussed.
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  • 45
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    Naunyn-Schmiedeberg's archives of pharmacology 272 (1972), S. 369-377 
    ISSN: 1432-1912
    Keywords: Trimethoprim ; Placental Transfer ; Distribution ; Elimination ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After a single i.v. administration of 50 mg/kg of Trimethoprim (TM) to rats in late pregnancy, a diffusion equilibrium of the folic acid inhibitor in the foetal organs is reached after 30–60 min. The TM levels in maternal as well as in foetal organs can have an inhibitory effect on folic acid reductase activity. The elimination of TM is lower in pregnant than in non-pregnant animals. The TM elimination of the foeti is dependent on the elimination capacity of the mother. Three-days-old rats eliminate TM some four times slower than mature animals owing to their reduced kidney development.
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  • 46
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    Naunyn-Schmiedeberg's archives of pharmacology 273 (1972), S. 352-365 
    ISSN: 1432-1912
    Keywords: Calcium Transport ; Small Intestine ; Rat ; in vitro ; in vivo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intestinal calcium (Ca) transport was studied in the rat jejunum by the in vitro perfusion technique of Fisher and Parsons and in the tied loop in vivo. Mucosal uptake and absorption of Ca was examined under the following conditions: rising intraluminal Ca-concentrations (0.5–128 meq/l); inhibition of energy dependent metabolism (2,4-dinitrophenol, N2, low temperature); net water flow, out of or into the intestinal lumen; addition of strontium (Sr); pretreatment with low Ca-diet and with 6-methyl-prednisolone. The concentration-dependent Ca absorption curve rose steeply at low Ca-concentrations but changed to a slowly rising straight line above 16 meq/l Ca++. In contrast, Ca uptake into the intestinal wall was directly related to Ca concentration, was linear from the beginning and paralleled the straight part of the absorption curve. Ca absorption was decreased by inhibition of energy dependent metabolism, addition of Sr and pretreatment with prednisolone. Pretreatment with low Ca diet increased Ca absorption and direction of net water flow (“solvent drag”) had no effect on it. Mucosal uptake of Ca was similar to Ca absorption except that metabolic inhibition increased Ca uptake but decreased Ca absorption. These results are compatible with the concept of a passive mucosal uptake and of an active absorption of Ca at low intraluminal Ca concentrations with additional passive component at high Ca concentrations.
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  • 47
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    Naunyn-Schmiedeberg's archives of pharmacology 274 (1972), S. 91-106 
    ISSN: 1432-1912
    Keywords: Choline ; Blood-Brain-Barrier ; Brain ; Rat ; Lecithin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the rat brain the concentration of choline increases with a velocity of 20.5 nMol/g×min immediately after decapitation. This is not due to postmortal disintegration of the tissue but to persisting biochemical reactions in the absence of blood flow. This rise of choline must be considered if the concentration of choline in the living animal is to be established. Taking this fact into account one arrives at a value of 27.5±1.7 nMol Choline/g wet weight. From the arterio-venous difference of choline concentrations it has been postulated that there is an efflux of 7.2±1.5 nMol/g×min from the brain into the blood. After i.v. injection of labelled choline the peak of the specific radioactivity of choline in the brain is reached in less than 1 min but amounts to only one tenth of the specific activity of choline in blood-plasma. The specific activities in both compartments decline in parallel. Thus it can be concluded a) that choline penetrates easily through the blood-brain barrier, but the concentration gradient is directed from brain to blood; and b) that choline is continuously formed in the brain, which process permanently dilutes the quantity of labelled choline and prevents the specific activities in blood and brain from becoming equal. The calculations of turnover-rates in the different reactions leading to the choline containing glycerophosphatides are based on the data obtained. On the basis of these findings it is proposed that in the brain phosphorylated derivatives of ethanolamine (phosphorylethanolamine, cytidinediphosphate-ethanolamine) can be methylated to form the respective choline derivatives.
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  • 48
    ISSN: 1432-5233
    Keywords: Cyclophosphamide treatment ; Guinea pig ; Experimental diabetes ; Immunodiabetes ; Immunosuppression ; Insulin resistance ; Islets of Langerhans ; Precipitating insulin antibodies ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Hyperglycémie, amélioration de la tolérance à l'insuline et modifications considérables à niveau des cellules B et A des ilots de Langerhans ont fait l'objet d'une observation, après immunisation par insuline et adjuvant, en cobayes produisant des anticorps anti-insuline précipitants. Le traitement par le cyclophosphamide inhibait la production d'anticorps anti-insuline, alors que la glycémie et la tolérance à l'insuline restaient aux mêmes niveaux qu'on pouvait vérifier chez les animaux de contrôle non immunisés. Même les îlots de Langerhans semblaient avoir subi des dommages moins importants par rapport à ceux des animaux qui n'avaient pas été traités par le cyclophosphamide.
    Abstract: Resumen En covayos productores de anticuerpos antinsulina precipitantes, tras inmunización con insulina y adyuvante, se ha podido observar: hiperglicemia, aumento de la tolerancia a la insulina y conspícuas modificaciones a cargo de las células A y B de las islas de Langerhans. El tratamiento con ciclofosfamida inhibía la producción de anticuerpos antinsulina, mientras la glucemia y la tolerancia insulínica permanecían en los mismos niveles que podían observarse en los animales de control no inmunizados. Las islas de Langerhans aparecían menos dañadas respecto a las de los animales no tratados con ciclofosfamida.
    Notes: Riassunto Iperglicemia, aumento della tolleranza all'insulina e cospicue modificazioni a carico delle cellule B ed A delle isole di Langerhans sono stati osservati, dopo immunizzazione con insulina in adiuvante, in cavie produttrici di anticorpi anti-insulina precipitanti. Il trattamento con ciclofosfamide inibiva la produzione di anticorpi anti-insulina, mentre la glicemia e la tolleranza insulinica rimanevano agli stessi livelli riscontrabili negli animali di controllo non immunizzati. Anche le isole di Langerhans apparivano meno danneggiate rispetto a quelle degli animali non trattati con ciclofosfamide.
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  • 49
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    Acta diabetologica 9 (1972), S. 655-687 
    ISSN: 1432-5233
    Keywords: Chinese hamster ; Diabetes ; Glycogen infiltration ; Kidney ; Nuclear glycogenosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Cette enquête sur l'ultra-structure du rein de hamsters chinois atteints de diabète a permis de relever des lésions glomérulaires légères, consistant en un épaississement non-homogène des membranes basales des vaisseux capillaires, des altérations de cellules de la mésange, une dilatation irrégulière des anses vasculaires. Sur la partie tubulaire, une accumulation de glycogène dans le cytoplasme des cellules de la partie distale et du tube collecteur ainsi que la présence de glycogène dans le noyau des animaux atteints d'un grave diabète et de kétose.
    Abstract: Resumen La presente investigación sobre la ultraestructura del riñón del hamster chino diabético, ha dado la posibilidad de poner en evidencia sutiles lesiones glomerulares, consistentes en el engrosamiento no homogéneo de las membranas basales de los vasos capilares, en alteraciones de las células del mesangio, en la dilatación irregular de las ansas; y, a cargo de la parte tubular, en una acumulación de glicógeno en el citoplasma de las células del tramo distal y del túbulo colector y en la presencia de glicógeno en el núcleo de los animales con diabetes grave y quetosis.
    Notes: Riassunto La presente indagine sulla ultrastruttura del rene di hamsters cinesi diabetici ha fatto rilevare fini lesioni glomerulari, consistenti in ispessimento non omogeneo delle membrane basali dei vasi capillari, alterazioni delle cellule del mesangio, dilatazione irregolare delle anse vascolari. A carico della parte tubulare, accumulo di glicogeno nel citoplasma delle cellule del tratto distale e del tubulo collettore; presenza di glicogeno nel nucleo negli animali con diabete grave e chetosi.
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  • 50
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    Cell & tissue research 126 (1972), S. 193-205 
    ISSN: 1432-0878
    Keywords: Spermatozoon ; Chilopoda ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Le spermatozoïde de Lithobius forficatus L. a été étudié grâce aux microscopes électroniques, classique et à balayage. Le spermatozoïde a une longueur d'environ 2 mm et comprend deux parties: la tête, avec l'acrosome et le noyau, et la queue, divisée en zone de liaison, pièce intermédiaire et pièce terminale. L'acrosome, entouré par du matériel fibrillaire exogène, a environ 4 μ de long sur 0,2–0,3μ de large. Le noyau spiralé (300 à 400 μ de long) est constitué d'un axe fibrillaire et d'une spire granulaire dans la région postérieure. La zone de liaison est composée de la partie basale différenciée du noyau et des parties antérieures du complexe flagellaire et de la pièce intermédiaire. La pièce intermédiaire, particulièrement longue (1,5 mm environ) est formée par le flagelle entouré de ses gaines et du manchon mitochondrial. La pièce terminale est un court prolongement flagellaire (6 à 7 μ). Les spermatozoïdes matures (prélevés dans les vésicules séminales) ont une structure mitochondriale légèrement différente de celle des spermatozoïdes prélevés dans le testicule.
    Notes: Summary The spermatozoon of Lithobius forficatus was investigated by transmission and scanning electron microscopy. The spermatozoon has a length of about 2 mm long, it is subdivided into a head with acrosome and nucleus, and a tail with a connecting piece, a middle piece and an end piece. The acrosome, surrounded by exogenous fibrillar material is about 4 μ long and 0.2–0.3 μ wide. The spiral nucleus (300–400 μ in length) consists of a fibrillar axis and of a whorl of granular material in the posterior part. The connecting piece is composed of the basal differentiated part of the nucleus and the anterior parts of the flagellar complex and middle piece. The latter is particularly long (about 1.5 mm) and consists of the flagellar complex and the mitochondrial sheath. The flagellar end piece is short (6–7 μ). Mature spermatozoa (seminal vesicles) have a mitochondrial structure slightly different from those within the testis.
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    Cell & tissue research 126 (1972), S. 261-277 
    ISSN: 1432-0878
    Keywords: Adrenal medulla ; Rat ; Cell types ; Secretion ; Influence of fixation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Nebennierenmark der Ratte wurde nach Anwendung verschiedener Fixationsmethoden untersucht. Nach Immersionsfixation mit Glutaraldehyd oder Osmiumtetroxyd finden sich in der Nebenniere sog. Mischzellen, helle Zellen, syncytiale oder plasmodiale Zellen, die von den Untersuchern als Artefaktbildungen angesehen werden. In allen Proben nach Perfusionsfixation wurden solche Artefaktbildungen niemals beobachtet. Bei Immersionsfixation wurde eine enge Beziehung zwischen Sekretgranula und Cytoplasmamembran beobachtet, was bei Perfusionsfixation selten der Fall war. Die heutigen Theorien über den Sekretionsmechanismus bei Nebennierenmarkzellen werden aufgrund der vorgelegten Ergebnisse diskutiert. Die Arbeit zeigt die wesentlichen Vorteile der Anwendung der Perfusionsfixation für die Untersuchung der Nebenniere.
    Notes: Summary The adrenal medulla of the rat was studied utilizing various methods of fixation. In adrenal medulla specimens after immersion fixation either with glutaraldehyde or osmium tetroxide, elements such as mixed, clear, syncytial, or plasmodial cells, believed to be of artifactual origin, are observed in all of this material examined. These elements are absent in the specimens prepared by perfusion fixation. In specimens prepared by immersion fixation, secretory granules are found in close proximity to the plasma membrane; this localization is infrequent after perfusion fixation. Current theories of the mechanism of secretion of adrenal medullary hormones are discussed on the basis of our results. This investigation demonstrates the advantage and necessity of perfusion fixation in the study of the adrenal medulla.
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  • 52
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    Cell & tissue research 126 (1972), S. 466-482 
    ISSN: 1432-0878
    Keywords: Macrophages ; Microtubules ; Enamel organ ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the enamel organ of rat incisors macrophages are present in the zone of matrix formation, the transitional zone, the enamel maturation and pigmentation zone. The macrophages accumulate adjacent to redifferentiating amelocytes in the transitional zone. The macrophages phagocytize fragments of disintegrating amelocytes. In addition to the well known complement of organelles the macrophages present an elaborated microtubular system, scattered, thick filaments, a cortical feltwork of thin filaments, and spherical nuclear bodies. The microtubules emanate from “attached” and free pericentriolar satellites and radiate aster-like towards the cell surface or into pseudopods or curve along the nuclear surface for long distances, often related to nuclear constrictions. It is suggested that the microtubular system plays a prominent role in directional movement of the macrophages. The cortical filaments, if contractile, may create the cytoplasmic flow necessary for the cell motility.
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  • 53
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    Cell & tissue research 127 (1972), S. 1-8 
    ISSN: 1432-0878
    Keywords: Parathyroids ; Anurans ; Crystals ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytoplasmic and nuclear crystalline inclusions are described in parathyroid secretory cells of adult frogs (Rana temporaria L.) and their possible significance is discussed.
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  • 54
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    Cell & tissue research 127 (1972), S. 34-49 
    ISSN: 1432-0878
    Keywords: Cephalic kidney insects ; Diplura ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'ultrastructure du rein labial céphalique deCampodea chardardi Condé a été étudiée. Cette néphridie comprend trois parties: le saccule terminal, le labyrinthe et le canal excréteur. Les cellules du saccule sont des podocytes typiques, contenant de nombreuses vacuoles de pinocytose et des inclusions diverses. La lumière est envahie par des micro-organismes bacilliformes. Le labyrinthe possède des cellules à indentations basales profondes avec de nombreuses mitochondries, et des microvilli distaux. Le canal excréteur débouchant sur la face ventrale du labium est caractérisé par la présence d'une intima cuticulaire. Le rein labial des Diploures a été comparé avec des organes segmentaires néphridiens d'autres Arthropodes, et avec le néphron des Vertébrés.
    Notes: Summary The ultrastructure of the cephalic labial kidney ofCampodea chardardi Condé has been studied. Each nephridium is subdivided into three segments: end-sac, coiled tubule and efferent-duct. The cells of the sacculus are typical podocytes, and contain numerous pinocytotic vesicles and various vacuoles. The lumen contains micro-organisms. The cells of the coiled tubule bear basal infoldings with numerous mitochondria and distal microvilli. The efferent duct terminates close to the ventral face of labium, and possesses characteristic cuticular intima. The labial kidney of Diplura is compared with published data on the nephridial organs of other Arthropods and Vertebrate nephron.
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  • 55
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    Cell & tissue research 127 (1972), S. 175-188 
    ISSN: 1432-0878
    Keywords: Vitelline membrane ; Chorion ; Ephestia ; Follicle cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural studies on developing egg chambers of the moth, Ephesita kühniella reveal that the precursors of the vitelline membrane are synthesized within follicle cells which are in contact with the oocyte. The vitelline membrane precursors appear to be synthesized by the rough-surfaced endoplasmic reticulum, and this material apparently moves to the Golgi cisternae where the definitive vitelline membrane precursor body is produced. The previtelline bodies are then secreted into the spaces between the oocyte and follicle cells, where they fuse to form a continuous membrane. Chorion formation begins with the deposition of a layer of tubules at the outer edge of the vitelline membrane which coalesce to form the inner edge of a thin, striated layer. In subsequent stages, several compartmented layers are rapidly secreted external to the striated layer, giving rise to the mature chorion.
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  • 56
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    Cell & tissue research 127 (1972), S. 356-373 
    ISSN: 1432-0878
    Keywords: Complex eye ; Formica polyctena ; Receptors ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Analyse der Feinstruktur des Komplexauges der Ameise Formica polyctena ergab, daß der dioptrische Apparat der insgesamt 750 Ommatidien aus einer lamellierten Cornealinse und einem euconen Kristallkegel besteht. Zwei Hauptpigmentzellen umgeben schalenförmig den Kristallkegel, 8 Nebenpigmentzellen schirmen das Ommatidium in seiner ganzen Länge von der Cornea bis zur Basalmembran ab. Jedes Ommatidium besteht in seinem distalen Teil aus 8 Retinulazellen, 2 gegenüberliegenden schmalen und je 3 gegenüberliegenden großen Sehzellen. Weiter proximal tritt eine 9. Retinulazelle hinzu. Die Mikrovillisäume der Sehzellen verschmelzen zu einem zentralen Rhabdom. Im distalen Teil sind die Mikrovilli in 3 Richtungen angeordnet. Es wird im besonderen die Orientierung der Mikrovilli zur Augenlängsachse und zur Ommatidien-Symmetrieachse untersucht. Auch die 9. Sehzelle bildet Mikrovilli. Das Rhabdom endet an 4 basalen Pigmentzellen. Auf den Mikrovillisaum folgt im Querschnitt des dunkel adaptierten Ommatidiums ein Kranz von großen intrazellulären Vakuolen. Die anschließende cytoplasmatische Zone der Retinulazellen enthält viele Pigmentgranula und Mitochondrien; multivesikuläre und multilamelläre Körper sowie Golgiapparate treten nur selten auf. Die funktionelle Bedeutung des Ommatidienaufbaues und die Verteilung der Organellen bei Dunkeladaptation werden diskutiert.
    Notes: Summary The fine structure of the compound eye of the ant Formica polyctena was investigated. The eye consists of a total of 750 ommatidia, each containing a dioptric apparatus of a lamellated cornea lens, a eucone-type crystalline cone, and 8 long pigment cells which surround the ommatidium for its total length, i.e. from the cornea to the basal membrane. Each ommatidium has in its distal portion 8 retinula cells—6 large plus 2 small ones. The retinula cells are arranged in such a way that 3 pairs of large cells, and the one pair of the small cells lie opposite each other. Further proximally, a 9th retinula cell is encountered. The fused, centrally located rhabdom is built up by the microvilli of all nine retinula cells. The rhabdom ends at 4 basal pigment cells. In dark adapted ommatidia, a ring of large intracellular vacuoles is to be seen immediately peripherally to the rhabdom. The outer, cytoplasmic zone of the retinula cells contains many pigment granules and mitochondria; multivesicular bodies, onion bodies and Golgi apparatus are of relatively rare occurrence. The functional significance of the ommatidial structure and the arrangement of the cell organelles in the dark adapted condition are discussed.
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  • 57
    ISSN: 1432-0878
    Keywords: Olfactory tubercle ; Rat ; Degeneration ; Synapse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The olfactory tubercle of the rat was studied by electron microscopy both in the normal and after ipsilateral olfactory bulb ablation at survival times of from 14 hours to seven days. Particular emphasis was placed on synaptic structures and their changes following the lesion. Normal synapses are similar to those described in previous studies and presynaptic profiles are of at least three types. Types-A and -B contain round vesicles and form asymmetrical contacts and type-C profiles contain flattened vesicles and form symmetrical contacts. There appear to be two major types of degenerative changes. The electron-lucent type predominates at early survival times and is seen first at 14 hours. These profiles show an early reduction in numbers of vesicles with mitochondrial swelling followed by shrinkage of the profile. These profiles become increasingly electron-dense at later survival times. The second major type of degenerating profile is initially electron-dense. The earliest changes in these profiles are an increased axoplasmic density and increased microtubular density and clumping without apparent loss of vesicles. These profiles also become progressively more electron-dense at longer survival times. The observations are discussed in relation to previous reports.
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  • 58
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    Cell & tissue research 124 (1972), S. 465-478 
    ISSN: 1432-0878
    Keywords: Anterior pituitary ; Mouse ; in vitro ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Anterior pituitaries of mice were incubated for periods up to four hours in Krebs-Ringer bicarbonate glucose gassed with 95% O2∶5% CO2. The incubated explants survived and retained a fine structure that approximated the condition in situ. The few necrotic cells were sharply localized, and were found to be due to initial mechanical damage to the tissue. Some cells of the six granulated types exhibited slight but significant changes attributable to the liberation from the hypothalamic control: in LTH cells there was a release of preexisting granules and a development of cell organelles, whereas in other cell types there was an inhibition of release of granules and an enhanced digestion of the accumulated granules by the lysosomal system. Follicular cells responded uniquely to the changed environment by hypertrophy of the cytoplasm and were found to phagocytize cell debris. A part of non-epithelial elements of the gland showed a tendency to modulate cytologically.
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  • 59
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    Cell & tissue research 124 (1972), S. 454-464 
    ISSN: 1432-0878
    Keywords: Lateral-line organ ; Eel (Anguilla japonica) ; Mechanoreceptor ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sensory epithelium of the lateral line organ of the common eel consists of two types of cells, (sensory and supporting). The sensory cell bears a kinocilium together with about 40 to 60 stereocilia on its surface. The kinocilium is situated either at rostral or at caudal margin of this cilial group. Such polarity of the cilial group of one cell is inverse to that of an adjacent cell. Two types of crystal-like inclusions exist in the sensory cells, consisting of granules 100 Å in diameter. Granules in one type are arranged regularly whereas those in the other rather irregularly. Two types of nerve endings exist at the base of sensory cells: one is predominant in number and contains few vesicles, accompanied by a dense spherical body surrounded by small vesicles in the sensory cell and the other is rare in number and contains many vesicles, accompanied by a small flat sac just beneath the plasma membrane of the sensory cell. The supporting cells contain numerous mitochondria, a well developed Golgi apparatus and rough-surfaced endoplasmic reticulum, and surround a sensory cell completely. Physiologic significance of some of these components is discussed.
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  • 60
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    Cell & tissue research 126 (1972), S. 335-347 
    ISSN: 1432-0878
    Keywords: Glandulae submaxillares ; Mammals ; Duct cell granules ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Discrete, PAS-positive granules of relatively uniform electron-density and size characterise the intercalated duct cells of mammalian submaxillary glands. Smaller, electron-dense organelles are seen in the cells at the junction of the intercalary-striated duct region in the guinea-pig. The large granules of variable electron-density which are observed in the proximal, modified intercalary cells in the rabbit closely resemble the granules in the acinar cells of the guinea-pig. Several populations of granules differing in size are found in the striated granular tubules of the rat and hamster; the organelles in the rat show two grades of electron-density whereas those in the hamster are uniformly dense. Numerous small granules with compactly arranged intragranular material occupy the apical part of the striated ducts of the cat, dog and rabbit. The chemical composition of each population of duct cell granules is unknown. The question whether granules containing kallikrein, trypsin-like enzymes and amylase are stored in the duct cells is discussed.
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  • 61
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    Cell & tissue research 126 (1972), S. 437-445 
    ISSN: 1432-0878
    Keywords: Eye ; Sarcophaga bullata ; Ommatidia ; Lamina ganglionaris ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary External and internal surfaces of the compound eye of the flesh fly, Sarcophaga bullata, were examined with a scanning electron microscope. A low patterned corneal nippleridge array and sparse setiform interfacetal hairs were observed on the corneal lens surface. Particular cleavage planes revealed outlines of the Semper Cells, their nuclei and distal terminations of photoreceptor cells. The latter, with their axonal processes, were visualized and described. These axons were noted traversing the external chiasma and entering the lamina ganglionaris where suggestions of synaptic contact were pointed out. The present descriptions were correlated with those taken from literature of the transmission electron microscope.
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  • 62
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    Cell & tissue research 127 (1972), S. 201-208 
    ISSN: 1432-0878
    Keywords: Spermatogenesis ; Rat ; Mitosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pattern of intercellular cytoplasmic bridges between rat spermatogonia and between spermatocytes is illustrated from electron microscopy of serial sections. Clones, or syncytia, containing as many as 22 connected spermatogonia and as many as 74 connected spermatocytes were observed. The absence of closed rings of cells agrees with the observation that intercellular bridges are the result of incomplete cell division, rather than cell fusion. The bridges thus are a record of spermatogonial divisions within a clone. In early spermatogonial generations there is a predominantly linear arrangement. The groups of spermatocytes have more side branches. From the presence of synaptonemal complexes it is concluded that the connected spermatocytes of a given clone are in about the same developmental stage. The pattern of intercellular bridges indicates, however, that not all nuclei in a clone undergo mitosis in the same cycle. The connected cells of a clone are therefore not all of the same generation. From unconnected bridges it is assumed that new clones originate from single cells or groups of spermatogonia which separate from an existing clone.
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  • 63
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    Cell & tissue research 130 (1972), S. 171-179 
    ISSN: 1432-0878
    Keywords: Tubuli seminiferi ; Rat ; Structure ; Contractility ; Organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Isolated pieces of seminiferous tubules of adult rats were grown in organ culture for up to 8 weeks in Petri dishes on the surface of nutrient agar. The medium consisted of newborn calf serum, Eagle's minimum essential medium, glutamate and antibiotics. This method allowed observation of the contractions of the seminiferous tubules in the culture. Contractility, light and electron microscopic structure and histochemically demonstrable activities of alkaline phosphatase and ATPase of the tubule walls were studied at 1-week intervals. The contractility and alkaline phosphatase activity were maintained in the tubule wall for 3 weeks, and the activity of ATPase was maintained for 5 weeks. The thin filaments of the myoid cells, which are responsible for the contractility, were seen with the electron microscope in tubules cultured for 5 weeks. The organ culture method described in the present paper seems to be valuable for studies concerning the functioning of the myoid cells of the seminiferous tubules and the possibility that this is regulated by hormones.
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  • 64
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    Cell & tissue research 130 (1972), S. 302-311 
    ISSN: 1432-0878
    Keywords: Gonadal development ; Sex determination ; Germ cells ; Mollusca ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the gonad, from hatching through sexual maturity and oviposition, has been studied in Arion ater rufus and Deroceras reticulatum. At hatching, the gonad is comprised of several acini. These acini are hollow structures, the walls of which are generally one or two cell layers thick. This cell layer consists of intermingled germinal and non-germinal cells. Eventually, each acinus is divided into two compartments (cortical and medullar) by a layer of auxiliary cells. The auxiliary cells appear to differentiate into Sertoli and follicle cells. These three non-germinal cell types appear to form an uninterrupted cell barrier that isolates the female germ cells in the cortex from the male germ cells in the medulla. Thus, although these animals are hermaphroditic, the male and female germinal lines differentiate in physiologically isolated compartments.
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  • 65
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    Cell & tissue research 130 (1972), S. 279-301 
    ISSN: 1432-0878
    Keywords: Gonadal development ; Sex determination ; Germ cells ; Mollusca ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A cytological study has been made, at the light- and electron-microscope levels, of gonadal development in Arion circumscriptus. The gonad appears to be ectodermal in origin and is composed of two cell lines—germinal and non-germinal. These two lineages are established in the embryo. The germinal line is first represented by primordial germ cells while the non-germinal line is first represented by auxiliary cells. The primordial germ cells differentiate into spermatogonia and oogonia, the auxiliary cells into Sertoli cells and follicular cells. Spermatogonia and oogonia differentiate about the time of hatching. All subsequent germ cells appear to differentiate from these initial populations of spermatogonia and oogonia. The concept of a germinal epithelium, as a cell layer in which germ cells differentiate from indeterminate germ cells throughout the life cycle, is not supported by this study. A model for sex determination of the germ cells is proposed based on the hypothesis that sexually non-determined primordial germ cells are distributed into two physiologically isolated compartments (a male medullar compartment and a female cortical compartment). The spermatogonia and oogonia then differentiate in two different microenvironments.
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  • 66
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    Cell & tissue research 131 (1972), S. 31-45 
    ISSN: 1432-0878
    Keywords: Synapse ; Ultrastructure ; Giant fibre ; Crayfish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of synapses between the cord giant fibres (lateral and medial) and the motor giant fibres in crayfish, Astacus pallipes, third abdominal ganglia have been examined. These electrotonic synapses are asymmetrical, they have synaptic vesicles only in the presynaptic fibre, and they have synaptic cleft widths normally of about 100 Å but narrowed to about 50 Å in restricted areas. Localized increases in density of the synaptic cleft and adjacent membranes also occur within a synapse, and synaptic vesicles are most tightly grouped at the membrane in such areas. Tight or gap junctions with 30 Å or narrower widths have not been found, but the junctions probably function in a similar way to gap junctions. Three small nerves are closely associated with the synapses between the giant fibres. One of these small nerves has round synaptic vesicles and is thought to be excitatory on morphological grounds; one has flattened vesicles and is thought to be inhibitory; and one is postsynaptic to the lateral giant and the two small presynaptic nerves. It is proposed that these small nerves modulate activity in the much larger giant fibre synapse.
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  • 67
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    Cell & tissue research 131 (1972), S. 47-62 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Lungfish ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neurohypophysis of the South American lungfish Lepidosiren paradoxa has been studied with light and electron microscopy, including the Falck-Hillarp technique for catecholamines. The pars nervosa hypophyseos is a well-marked, dorsally located subdivision of the pituitary gland composed of lobes or follicles, each one constituted of a central core of ependymal cells, a subependymal hilar region made up of nerve fibers and a peripheric palisade zone of nerve endings which contact capillary vessels. Four types of neurosecretory axons can be distinguished under the electron microscope. Type I, the most common, contains spherical elementary granules of high electron density, 1500–1800 Å in diameter. The scarce type II axons contain irregularly-shaped elementary granules. Type III contains only small clear vesicles, 400–600 Å in diameter. Type IV, mostly present in regions of the gland contacting the pars intermedia, contain large granulated vesicles, 900–1000 Å in diameter. The Falck-Hillarp technique revealed axons with a positive reaction for catecholamines at sites corresponding approximately to the location of type IV of the electron microscope. Ependymal cells are of large size, linking the cerebrospinal fluid, the nerve endings and the blood vessels. A conspicuous membrane-bound, spherical dense material, 1400–2000 Å in diameter, is observed in both the apical and vascular processes of these cells. The ependymal processes which traverse the hilar and palisade regions contain structures resembling degenerated neurosecretory axons. These results are discussed in relation with the currently available information on the comparative anatomy of the pars nervosa. The possible functional significance of ependymal cells and of each type of axon are also discussed. This study was aided by the following grants: NIH NS 06953 to Prof. De Robertis, Consejo Nacional de Investigaciones Científicas y Técnicas to Prof. Zambrano, Comisión de Investigaciones Científicas de la Provincia de Buenos Aires and Comisión de Investigaciones Cientificas de la Universidad Nacional de la Plata: to Prof. Iturriza. The authors are indebted to Prof. De Robertis for his generosity in granting us his laboratory facilities, and to Dr. F. J. J. Risso and Mr. A. Fernández (Resistencia, Chaco) who provided the specimens used in this study. The able microtechnical assistance of Miss L. Riboldazzi and Mrs. R. Raña and the photographic work of Mr. A. Saenz are much appreciated.
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    Cell & tissue research 131 (1972), S. 99-107 
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Exocytosis ; Micro-pinocytosis ; Releasing factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Exocytosis has been demonstrated by electron microscopy in the external zone of the median eminence of the rat. Exocytotic profiles have been observed in nerve fibres characterized by the presence of granular vesicles with median diameters of 90–103 nm and agranular vesicles of about 50 nm. In addition to the small agranular vesicles, coated vesicles of the same size have been found in many nerve fibres, suggesting that at least part of the agranular vesicles in the median eminence originate by micro-pinocytosis. The nature of the fibres showing exocytosis is discussed. Attention is drawn to the possibility of identifying types of fibres in the median eminence by the occurrence of exocytosis.
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  • 69
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    Cell & tissue research 132 (1972), S. 193-201 
    ISSN: 1432-0878
    Keywords: Branchial glands ; Cephalopods ; Haemocyanin synthesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The paired branchial glands in cephalopods are essential for life. The electron microscope reveals them to consist of cells containing masses of endoplasmic reticulum organised in parallel arrays together with pale areas between the reticulum that contain vacuoles. All three regions of the cells contain masses of haemocyanin particles and it is suggested that the gland is the site of haemocyanin synthesis, the particles being made amongst the endoplasmic reticulum at discharged into the pale areas and vacuoles before being released into the general circulation.
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  • 70
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    Keywords: Islets of Langerhans ; Grass-snake ; Crystalline B-granules ; Ultrastructure ; Crystallography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Kristalline B-Granula im Pankreas der Ringelnatter besitzen die Form von Rhombendodekaedern (a ≈ 11 nm, kubisch-raumzentriertes Gitter). Diese Diagnose wird abgeleitet von den Ergebnissen der dreidimensionalen Rekonstruktion von Serienschnitten, der optischen Diffraktometrie und aus dem Vergleich mit Kristallmodellen. Die Bedeutung kristalliner B-Granula wird erörtert.
    Notes: Summary Crystalline B-granules of grass-snake islets of Langerhans have been shown to possess the shape of rhombic dodecahedra (a ≈ 11 nm, cubic body-centered lattice). Three-dimensional reconstructions from serial sections, optical diffractometry and comparison with crystal models were the techniques utilized. The significance of crystalline B-granules is discussed.
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    Cell & tissue research 132 (1972), S. 15-24 
    ISSN: 1432-0878
    Keywords: Digestive diverticula ; Bivalves ; Peroxisomes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy of the digestive diverticula of the protobranch bivalve, Nucula sulcata, revealed the presence of peroxisomes in the basal regions of the epithelial cells lining the main and secondary ducts, and in the digestive and secretory (basophil) cells of the tubules. Those in the secretory cells are elongate and somewhat flattened, while those of the other cell types have a spherical form. Two distinct types of nucleoid are normally present within the secretory cell peroxisomes, one compact, crystalline, and finely polytubular, the other comprising isolated secondary tubules arranged in a linear series across the width of the organelle. The peroxisomes of the digestive and duct cells contain coarsely polytubular cores arranged in two clusters orientated more or less at right angles; the duct cell peroxisomes may also contain a second nucleoid in the form of a compact finely polytubular core. Sections incubated in a medium containing 3,3'-diaminobenzidine (DAB) and hydrogen peroxide reveal an electron dense reaction product within the peroxisomes of all the cell types. Catalase is considered to be responsible for the reaction.
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    Cell & tissue research 132 (1972), S. 67-78 
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    Keywords: Salivary glands ; Octopus ; Secretory fibers ; Synapse ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les nerfs sécréteurs pénètrent dans l'épithélium des tubules au niveau du hile de la glande. Leurs subdivisions se disposent entre les cellules épithéliales ou leurs replis, et gardent toujours une situation extracellulaire. Les plus gros faisceaux d'axones sont encore entourés par des cellules satellites qu'on n'arrive plus à discerner autour des faisceaux moins importants ou autour des fibres isolées. Les axones sont alors directement au contact des cellules glandulaires. On a pu trouver des synapses neuro-glandulaires avec des spécialisations membranaires asymétriques comparables à celles décrites dans le système nerveux central des Vertébrés. Les fibres sécrétrices variqueuses contiennent d'autre part des vésicules de types variés, semblables à celles des troncs sécréteurs et moteurs du canal, et à celles des fibres motrices de la glande. La signification de ces vésicules a été discutée en relation avec l'existence possible d'amines biogènes diverses dans les fibres nerveuses.
    Notes: Summary The secretory nerves enter the tubule epithelium at the level of the gland hilus. Their subdivisions being located between the epithelial cells or their infoldings, have always extracellular position. Satellite cells still surround the largest axon bundles, but are no longer discernable round the smaller bundles or isolated axons which are thus in direct apposition with glandular cells. Neuro-glandular synapses, with asymetric membrane specialisations similar to those found in the central nervous system of vertebrates, have been found. The varicose secretory fibers contain various types of vesicles, similar to those found in the secretory or the motor trunks at the duct level, or in the gland motor fibers. The significance of these vesicles is discussed, in reference to the possible existence of various biogenic amines in the nerve fibers.
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  • 73
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    Cell & tissue research 132 (1972), S. 131-146 
    ISSN: 1432-0878
    Keywords: Nervous tissue ; Tardigrada ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Nervengewebe von Macrobiotus hufelandi zeichnet sich durch stark verzweigte pseudunipolare Nervenzellen und relativ wenige Gliazellen aus. Die Neurone besitzen rauhes ER, freie Ribosomen, zahlreiche Mitochondrien, einen wenig ausgeprägten Golgi-Apparat und einen elektronenlichten Kern. In ihren Axonen finden sich Vesikel und Einschlüsse unterschiedlicher Größe und Zusammensetzung. Die Gliazellen verzweigen sich stark und besitzen glattes ER, viele freie Ribosomen und einen elektronendichten Kern. Ganglien und Nerven werden nur durch eine dünne Neurallamelle vom extraganglionären Raum getrennt. Die morphologische Ausbildung des Nervengewebes wird im Hinblick auf die extreme Lebensweise der Tardigraden diskutiert.
    Notes: Summary The typical elements of the nervous tissue of Macrobiotus hufelandi are strongly ramified pseudunipolar neurons and a small amount of glial cells. In the perikarya of neurons there are rough ER, free ribosomes, many mitochondria, a poor Golgi-apparatus, and an electron-light nucleus. Nerve fibers contain masses of vesicles and inclusions of different size and composition. The ramifying glial cells have smooth ER, many free ribosomes, and an electron-dense nucleus. Ganglia and nerves are separated from the extraganglionic cavity by a thin acellular sheath (neural lamella). The organization of the nervous tissue is discussed with regard to the extreme conditions of environment of the tardigrades.
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  • 74
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    Cell & tissue research 132 (1972), S. 451-472 
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Myxine glutinosa ; Cell types ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of adenohypophysial cells in the Atlantic hagfish (Myxine glutinosa) is described and the morphological evidence for secretory activity is discussed. A scarcity of secretory granules is characteristic of the adenohypophysis of Myxine. Two cell types having the appearance of protein hormone producing cells can be identified. Type 1 has dense membrane-bound granules with a calculated mean diameter of 88 nm while type 2 has larger granules with a mean diameter of 176 nm. The release of secretory granular material follows mainly the “membrane-release” pattern. It is suggested that cell type 1 may produce a hormone which is similar to ACTH/MSH and type 2 another hormone similar to STH/LTH. The basophilic cells contain a secretory material which is similar to the mucus produced in the epithelial mucus cells. Several structural modifications are considered to represent functional compensations for the absence of vascular elements in the gland. Among these are a cytoplasmic tubular system, certain long agranular cells together with long granule-containing projections from cell types 1 and 2, and foliate or finger-like invaginations of the basal lamina.
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  • 75
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    Cell & tissue research 132 (1972), S. 553-562 
    ISSN: 1432-0878
    Keywords: Basement membrane ; Brain ventricles ; Rat ; Subependymal labyrinths ; Light- and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Mit der Perjodsäure-Bisulfit-Aldehydthionin-Färbung (Specht) lassen sich am ganzen Ventrikelsystem des Rattengehirns sub- und interependymale Strukturen lichtmikroskopisch nachweisen, die elektronenmikroskopisch als Basalmembranlabyrinthe (BML) identifiziert werden können. Verschiedene Formen dieser BML lassen sich unterscheiden. Sie stehen in Verbindung mit subependymalen Kapillaren. Die Verteilung der BML wird in Ventrikelkarten dokumentiert.
    Notes: Summary Sub- und interependymal structures, being demonstrable by a period-acid-bisulfit-aldehydthionine-method (Specht), occur in the whole ventricular system by light microscopy. They can be identified electron microscopically as basement membrane labyrinths (BML). Different shapes of these BML can be distinguished. They are in communication with the basement membrane of subependymal capillaries. The distribution of BML is documented in “ventricular maps”.
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  • 76
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    Cell & tissue research 133 (1972), S. 35-46 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Fowl ; Liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the liver parenchymal cell from immature pullets and from immature and young mature cockerels has been studied. The results demonstrated that the fowl's hepatocyte is structurally very similar to that of other birds and, in spite of certain morphological differences between the livers of birds and mammals, is also very similar in structure to the liver cell of mammals.
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  • 77
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    Cell & tissue research 130 (1972), S. 312-317 
    ISSN: 1432-0878
    Keywords: Aphid cornicle ; Basal lamina ; Oenocyte ; Holocrine secretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light- and electron-microscopic observations on the cornicles of the rose aphid Macrosiphum rosae are presented, and discussed in relation to conflicting interpretations of cornicle structure and function. Lipid filled cornicle secretory cells occupy the lumen of the cornicle and extend into the abdominal cavity. The aphid is readily induced by mechanical stimuli to release cornicle secretory cells from a pore at the tip of the cornicle. The holocrine secretory cells are disrupted and release their lipid contents on leaving the body. They are enclosed within an acellular membranous sac that is apparently identical in structure with the basal lamina of the epidermis. The ultrastructure and anatomical relationships of the cornicle secretory cells suggest that they are oenocytes invaginated with the epidermal basal lamina, and are not anatomically or embryologically related to fat body.
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  • 78
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    Keywords: Ultimobranchial glands ; Urodeles ; Cell types ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The fine structure of the ultimobranchial (UB) glands of two common laboratory urodeles, viz., larval axolotls, Ambystoma mexicanum Shaw and adult Pleurodeles waltlii Micahelles, is described and compared in what is believed to be the first ultrastructural report on urodele UB glands. The axolotl UB gland shows a wide variety of form, being represented by an elongated diffuse series of follicles and sometimes by one or two large discrete terminal follicular bodies. In these axolotl UB glands up to four cell categories are distinguishable including a tonofilamentous cell and a secretory cell that is possibly homologous with calcitonin-producing C cells of anurans or other vertebrates. These two cell categories are also found in the Pleurodeles gland. The possible significance of the various cells is considered.
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  • 79
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    Cell & tissue research 134 (1972), S. 205-225 
    ISSN: 1432-0878
    Keywords: Diabetes insipidus ; Rat ; Hypothalamo-neurohypophysial system ; Synthesis of hormones ; Light- and Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The general ultrastructural features of the hypothalamo-neurohypophysial system in rats with hereditary hypothalamic diabetes insipidus (DI-rats, Brattleboro strain) are described. There is no decisively distinguishing difference between the neurons of the supraoptic and paraventricular nuclei. The neurons of both nuclei show signs of active protein synthesis. The perikarya of the neurons are markedly hypertrophic, the nuclei are large and the nucleoli prominent. In the cytoplasm there are numerous ribosomes, abundant rough-surfaced endoplasmic reticulum and extensive Golgi complexes. However, very few neurosecretory granules are to be seen. The axons of the hypothalamo-neurohypophysial tract are likewise enlarged and the paucity of neurosecretory granules is a striking feature also in the area of the tract. The majority of nerve endings in the posterior pituitary of DI-rats are devoid of neurosecretory granules. Microvesicles are abundant in the nerve endings and there are findings which suggest that microvesicles are involved either in endoor exocytosis. The signs of active protein synthesis and the concomitant paucity of neurosecretory granules are interpreted to imply transportation of the secretory proteins in an extragranular phase. The possible mode of release of the secretory proteins from the nerve endings and the role of microvesicles therein are discussed.
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  • 80
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    Cell & tissue research 134 (1972), S. 255-271 
    ISSN: 1432-0878
    Keywords: Hepatopancreas ; Limulus ; Gap junctions ; Calcium spherules ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the hepatopancreas and associated tissues of Limulus is described. All hepatopancreatic tubules contain L- and D-cells. L-cells exhibit apical pinocytosis and contain many different types of inclusions, including lipid containing calcium spherules of unique structure. They also produce a complex secretory product released by apocrine secretion. D-cells contain much rough endoplasmic reticulum, and show other evidence of active protein synthesis. They produce a single type of secretory granule released by merocrine activity. The appearance of L- and D-cells in tubules of various sizes and in fed and starved animals is described. Both cell types may produce digestive enzymes and absorb and transport nutrients to the hemolymph, but neither serves as a major storage site. Storage is an important function of the intertubular R-cells. The appearance of R-cells in fed and starved animals is described. A previously undescribed hemocyte is reported, as are apparent gap junctions between L- and R-cells. A structural and functional comparison of these glands with those of other arthropods is presented.
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  • 81
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    Cell & tissue research 134 (1972), S. 273-282 
    ISSN: 1432-0878
    Keywords: Swim Bladder ; Gas gland cells ; Misgurnus fossilis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the wall of the rudimentary rear chamber in the swimbladder of the pond-loach was studied. The morphological features of a majority of the cells, as well as the presence of micro-rete mirabile, suggest that epithelial components in the wall of this organ represent a structural and functional equivalent of the gas gland.
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  • 82
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    Cell & tissue research 131 (1972), S. 429-436 
    ISSN: 1432-0878
    Keywords: Hormone granules ; Thyroid (C-cells) ; Anterior Pituitary ; Ultrastructure ; Freeze-etching method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Gefriergebrochene Präparate (mit und ohne Ätzung) der Adenohypophyse und der C-Zellen der Schilddrüse von Ratte und Meerschweinchen wurden elektronenmikroskopisch untersucht. Bei den Hormongranula dieser Zellen verlaufen die Bruchflächen im allgemeinen zwischen den beiden Membranflächen oder zwischen Granulum-Inhalt und Membran. Nur relativ selten werden Granula quergebrochen. Auf beiden Hälften der gespaltenen Membranen der C-Zellgranula werden etwa mit gleicher Häufigkeit Proteinpartikel (100–200 Å) gefunden. Bei den Granula der somatotropen Zellen treten auf der dem Plasma anliegenden Membranhälfte deutlich mehr Proteinpartikel auf als auf der dem Granuluminhalt anliegenden Hälfte. Der Inhalt der somatotropen und C-Zellgranula erscheint bei dieser Präparationsmethode aus einer dichten Packung von 80–100 Å großen Partikeln zu bestehen. Eine besonders strukturierte Zone zwischen Membran und Granuluminhalt konnte bei den bisherigen Untersuchungen nicht festgestellt werden. Durch Ätzung der Gefrierbrüche ließen sich keine zusätzlichen strukturellen Details der Granula darstellen. Eine durch Auswertung von stereoskopischen Aufnahmen gewonnene Größenverteilungskurve für die C-Zellgranula wird vorgelegt.
    Notes: Summary Freeze-fractured preparations (with and without etching procedures) of guineapig and rat thyroid (C-) cells and anterior pituitary (somatotropic-) cells have been investigated with the electron microscope. The hormone granules of these cells in general split either between the two lamellae of their unit membrane or between the granule contents and the unit membrane. Only rarely cross-broken granules have been observed. Inner and outer lamella of the unit membrane of the C-cell granules contain in more or less similar frequency moderate amounts of protein particles of 100–200 Å diameter. In case of the somatotrophs the outer lamella contains higher numbers of these particles than the inner one. The contents of the C-cell and somatotroph granules seems to consist of densely packed 80–100 Å particles. A particular zone between contents and membrane (as observed on micrographs with conventional electron microscopy) could not be detected on freeze-fractured preparations. The etching procedure does not reveal additional details of the granule structure. A size distribution curve of the C-cell granules as determined from stereo-pairs, is given.
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    Cell & tissue research 131 (1972), S. 497-517 
    ISSN: 1432-0878
    Keywords: Granulosa cells ; Oocyte ; Pig ; Mitochondria ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pig oocytes and their surrounding granulosa cells obtained from mature Graafian follicles at a stipulated time near to ovulation were studied in some details electronmicroscopically. Particular emphasis is given to the corona radiata cell processes and to the heterogeneous population of mitochondria in the oocyte. The corona radiata cell processes contain various components such as filaments, mitochondria, multivesicular bodies and lipid droplets in their matrix. The contact relationship of the corona radiata cell processes to the oocytes is maintained by desmosomes. Usually, the two parallel surface membranes forming the desmosome are separated by a space of about 200 Å. Occasionally, the two membranes approximate each other to form a junction having a “gap” of about 70 Å. Apparently the membranes become fused in some regions. Of particular interest is the distribution and structural characteristics of the single-membrane-bounded structures, and their relationship to the cytomembranes and the mitochondria. On the basis of the present and earlier (Norberg, 1972) observations, the question arises whether the formation and development of mitochondria of pig oocytes depend, at least partly, on a metamorphosis of single-membrane-bounded structures derived from less complex membraneous elements. Final conclusions concerning this problem demand integrated morphological and biochemical investigation regarding the biosynthesis of mitochondria.
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    Cell & tissue research 132 (1972), S. 25-34 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Perivascular cells ; Neurosecretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The purpose of this study is to investigate the ultrastructural features of perivascular cells as found in the neural lobe of the hypophysis. In particular, an inquiry was made into the nature of the relationship of such cells to neurosecretory fibers and endings. The latter, in fact, are often invaginated within the perivascular cells and enveloped by their processes; furthermore, they often reveal a certain number of empty granules as well as characteristics of degenerative nature. In the course of this study the localization of the perivascular cells has been investigated as well as that of their processes within the extensive interlobular network typical of the hypophysial neural lobe of rodents. Based on the data gathered, the hypothesis is put forward that the perivascular cells play an important role in the turnover of neurosecretory endings, both under physiological and experimental conditions, contributing thereby to the release of post-hypophysial hormones.
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    Cell & tissue research 132 (1972), S. 51-65 
    ISSN: 1432-0878
    Keywords: Salivary glands ; Octopus ; Innervation of musculature ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les fibres nerveuses, souvent composées, qu'on peut trouver dans le tissu conjonctif séparant les fibres musculaires du canal, ou les tubules de la glande, sont très comparables morphologiquement aux fibres des troncs moteurs. Leurs cellules satellites, qui contiennent de grosses inclusions, nombreuses et très denses aux électrons, engainent les axones pratiquement jusqu'au niveau des terminaisons. Les jonctions neuromusculaires sont caractérisées par l'accumulation de petites vésicules claires, accompagnées de quelques vésicules plus grandes et à »coeur« dense. Les axones présentent aussi le long de leur trajet des segments plus ou moins dilatés où existent des vésicules de types très variés, et dont la signification est discutée.
    Notes: Summary Nervous fibers, often composite, can be found in the connective tissue between the duct muscular fibers, or the gland tubules. They are morphologically similar to the motor trunks fibers. Their satellite cells, containing numerous electron-opaque large inclusions, can be seen round the axons nearly to the nerve endings. Neuromuscular junctions are characterized by the accumulation of small clear vesicles, intermingled with some larger dense-cored vesicles. Axonal swellings, with numerous vesicles of various types, can also be seen along the course of the nerve fibers; their significance is discussed.
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    Cell & tissue research 132 (1972), S. 95-106 
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    Keywords: Olfactory sensilla ; Insects ; Necrophorus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Auf dem Endglied der Antenne von Necrophorus wird eine neue Sensillenform als Sensillum coelosphaericum beschrieben. Anhand von Merkmalen des cuticulären Apparates werden 2 Typen dieses Sensillums unterschieden. 2. Die Wand des cuticulären Apparates ist von einem Porensystem durchbrochen, das als reizleitende Struktur angesehen werden kann. Abweichend vom Porensystem basiconischer Sensillen finden sich bei den Sensilla coelosphaerica statt der Porentubuli sackförmige Bildungen, die aus einem dreidimensionalen Gitterwerk von miteinander vernetzten Filamenten bestehen. Diese Filamentsäcke enden bei Sensillum coelosphaericum Typ I in Einbuchtungen der 3. Hüllzelle, die hier den cuticulären Apparat auskleidet; bei Typ II grenzen sie an den äußeren Liquorraum. 3. Bei beiden Typen der Sensilla coelosphaerica werden die Dendriten auch innerhalb des cuticulären Apparates von einer Scheide umgeben. Das reizleitende System reicht nicht bis in unmittelbare Nähe der Dendriten. Die räumliche Anordnung der Strukturen führt zu der Auffassung, daß Duftmoleküle die Dendritenmembran nicht allein durch Grenzflächen-Diffusion erreichen Können.
    Notes: Summary 1. A new type of olfactory sensilla, named Sensillum coelosphaericum, was found on the distal segment of the antenna of the Carrion beetle Necrophorus. Two types of sensilla are differentiated by characteristics of their cuticular apparatus. 2. The wall of the cuticular apparatus is penetrated by pores which may function in the conduction of stimuli. The sensilla coelosphaerica differ from the basiconic sensilla in that they do not have pore tubules but have sac-like structures consisting of a three-dimensional network of filaments. In sensillum coelosphaericum type I, these sacs end in infoldings of a third enveloping cell which in this type coats the inside of the cuticular apparatus; in type II, on the other hand, the sacs of filaments border the outer liquor space. 3. Within the cuticular apparatus in both types of sensilla coelosphaerica, the dendrites are surrounded by a dendritic sheath. The stimulus-conducting system does not contact the dendrites. The arrangement of these structures implies that odour molecules can also reach the dendrite membrane by other means than surface diffusion.
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    Cell & tissue research 135 (1972), S. 275-286 
    ISSN: 1432-0878
    Keywords: Oöcyte ; Resorption ; Locust ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The changes in the ultrastructure of the oöcyte and associated follicle cells during oösorption in Locusta migratoria migratoroides are described. Throughout the process the follicle cells act in a phagocytic manner and invade the oöplasm. Localizatio of acid phosphatase activity indicates that at the start of resorption the Golgi complexes of the follicle cells begin to produce lysosomes on a large scale, and that these are utilised in the breakdown of yolk spheres which have been taken up from the oöcyte. Partly degraded yolk spheres are collected together along with other cell organelles into cytolysomes. The significance of large numbers of microtubules within the follicle cells and of microvillar borders between the cells in late stage resorbing bodies is discussed.
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    Cell & tissue research 133 (1972), S. 163-179 
    ISSN: 1432-0878
    Keywords: Excretory organ ; Ileum ; Blatella germanica ; Ultrastructure ; Microprobe analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'iléon de Blatella germanica est un important segment d'accumulation minérale. Les nombreuses concrétions d'origine ergastoplasmique, contiennent du phosphore, du chlore, du calcium, du magnesium, du potassium et du fer dans un stroma glycoprotéique. La paroi de ce segment protodéal est constituée d'un type cellulaire unique caractérisé par la présence de feuillets apicaux et d'invaginations basales, différenciations membranaires décrites dans d'autres organes de transit, mais dont la coexistence constitue l'originalité de l'iléon. La signification physiologique de ce segment digestif est discutée.
    Notes: Summary The ileum of Blatella germanica is an important proctodeal segment of mineral accumulation. The numerous concretions, elaborated by the ergastoplasm, contain P, Cl, Ca, Mg, K and Fe in a glycoproteic matrix. The epithelium of this segment is composed by only one type of cells which are characterized by apical leaflets and basal infoldings. These membraneous differenciations have been already described in other transit organs, but their coexistence is typical of the ileum. The physiological significance of this digestive segment is discussed.
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    Cell & tissue research 133 (1972), S. 289-325 
    ISSN: 1432-0878
    Keywords: Nematosomes ; Neurons ; Substantia nigra ; Rat and Cat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Distinctive cytoplasmic inclusions, termed nematosomes, have been identified in the neurons, but not in the glial cells of the substantia nigra in the rat and the cat. These organelles which lack a limiting membrane consist of an entanglement of more or less tightly packed microfilaments or filamentous strands. According to the tridimensional arrangement of their filamentous components, as well as to their size and boundary, the nematosomes usually display several structural types: (a) round or oval, dense, filamentous bodies; (b) reticular inclusions with or without excavated centers; (c) ill-defined small aggregates of fine filaments. At higher magnification, each microfilament or filamentous strand, whatever the type of nematosome, is itself composed of similar subunits, about 20 Å in diameter. It should be pointed out that the latter subunits may be fine deposits of heavy metal on structural components of nematosomes, which appear to be similar in every structure. The ultrastructural organization of a given nematosome may vary from one portion to another. The functional significance of such structural variations from one nematosome to another, and even within a given nematosome, could not be elucidated by means of our ultrastructural study, although additional cytochemical and radioautographic work may throw light on this problem. These cytoplasmic bodies are present in the perikaryon of most neurons and one or more inclusions are usually observed in the same nerve cell. They are infrequently seen in the dendritic or axonal processes. The nematosomes are closely associated with the other cytoplasmic organelles filling the ground substance of neurons by means of microfilaments projecting from their surface. These cytoplasmic inclusions are, however, most frequently linked to surrounding free ribosomes and rough ER profiles. The association of free ribosomes with excavated nematosomes, which in turn contain neurofilaments in their core, suggests that these structures consist, partly at least, of precursor material which is assembled into the structural proteins of the neurofilaments after being synthesized by the neighbouring ribosomes. No special relationship with the neurotubules has been noticed. Nematosomes have also been found in structural relationship with other organelles, i.e. the smooth tubules and vesicles, the Golgi apparatus, the coated vesicles, the lysosomes and the mitochondria. The nematosome may be also closely associated with the subsynaptic web of axosomatic synapses and these two cytoplasmic components display many structural similarities. In the light of these and previously reported observations, it would appear that nematosomes are not incidental cytoplasmic inclusions, but common organelles of certain types of neurons.
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    Cell & tissue research 125 (1972), S. 143-175 
    ISSN: 1432-0878
    Keywords: Skin ; Cephalopods ; Chromatophores ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rapid, physiological color changes seen in the skin of cephalopods are due to a unique anatomical system composed of chromatophore organs and iridophores. The morphology and ultrastructure of the chromatophores was studied in the squids Loligo pealii Lesueur and Loligo opalescens Berry. A three-dimensional model of a brown chromatophore was reconstructed from serial sections for the electron microscope. The chromatophore organ is composed of a central nucleated pigment cell, 10–30 obliquely striated muscle cells (radially arranged on the equator of the pigment cell), axons, Schwann cells, and sheath cells. The pigment cell consists of a central aggregation of pigment granules and surrounding peripheral cytoplasmic compartments. These regions are incompletely separated by an electron-dense, sac-like structure, the pigment container. Proximal portions of a muscle cell contact the pigment cell in regions called myo-chromatophore junctions. Neuromuscular and myo-muscular junctions are also present. The results presented are discussed in terms of previous morphological and physiological studies of chromatophores.
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    Cell & tissue research 125 (1972), S. 176-190 
    ISSN: 1432-0878
    Keywords: Skin ; Cephalopods ; Iridophores ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two populations of iridophores are responsible for the iridescent color of the squids Loligo pealii and Loligo opalescens. The superficial group, the short iridophores, underlie the chromatophores and are associated with muscle cells of the skin. The long iridophores, a deeper-lying group, are arranged in a dense sheet. The ultrastructure of iridophores was described, including iridosomes, iridosomal platelets and iridosomal tubules. The observations were discussed in terms of adaptive coloration in these animals.
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  • 92
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    Cell & tissue research 125 (1972), S. 210-228 
    ISSN: 1432-0878
    Keywords: Regio olfactoria ; Teleosts ; Anguilla anguilla ; Ultrastructure ; 3 Different receptor types
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Flimmerepithel von Anguilla anguilla besteht aus 4 Zellarten: Flimmerzellen, Stützzellen, Basalzellen und Schleimbecherzellen. Flimmerzellen enthalten im oberen Zelldrittel zahlreiche Mitochondrien und tragen an ihrer Oberfläche bis zu 140 Kinocilien. Die Basalkörper dieser Kinocilien haben lange Wurzelfilamente, von denen ein Teil ins Zellinnere zieht; der andere Teil verläuft parallel zur Oberfläche und verbindet benachbarte Basalapparate. — Ein Übergangsepithel verknüpft das Flimmerepithel mit dem Riechepithel. Im Riechepithel finden sich außer den Zellarten des Flimmerepithels die Rezeptoren. Bei einheitlichem Aufbau des Zellkörpers lassen sich aufgrund rein morphologischer Unterschiede der Vesiculae olfactoriae 3 Rezeptortypen unterscheiden: 1. Cilien-Rezeptor, 2. Mikrovilli-Rezeptor und 3. „Pfriem“-Rezeptor. — Der Cilien-Rezeptor trägt unterhalb der Vesicula olfactoria in einer Einschnürung 4–8 sensorische Cilien, die alle auf gleicher Höhe entspringen. Zwei gegenüberliegende sensorische Cilien schließen einen konstanten Winkel von 60° ein. — Der Mikrovilli-Rezeptor trägt auf seiner abgerundeten Vesicula olfactoria 30 bis 60 Mikrovilli von 0,1 μm Dicke und bis zu 5 μm Länge. Der Mikrovillus wird von einem zentralen, 160 Å weiten, Tubulus durchzogen. Unterhalb der Vesicula olfactoria liegen mehrere Centriolen. Die Rezeptornatur dieser Zellen wird durch ein Axon unterstrichen. — Der „Pfriem“-Rezeptor besitzt eine 0,8 μm breite und bis zu 4 μm lange Vesicula olfactoria ohne sensorische Cilien und ohne Mikrovilli. Im Lumen der Vesicula olfactoria befinden sich neben Neurotubuli auch Fibrillen von 40–50 Å Durchmesser, die gebündelt auftreten. An der Basis des Köpfchens liegen mehrere Centriolen.
    Notes: Summary The ciliary and olfactory epithelia of the olfactory folds in Anguilla anguilla were studied with the electron microscope. The ciliary epithelium is composed of ciliary cells, supporting cells, basal cells, and mucous cells. The ciliary cells contain numerous mitochondria in their apical portion and bear up to 140 cilia. The ciliary basal bodies have rootlets, some of which project towards the central part of the cell, and others parallel to the cell surface thereby connecting neighbouring basal bodies. A transitional epithelium is located between the ciliary and olfactory epithelia. The olfactory epithelium is composed of the same 4 cell types of the ciliary epithelium and besides contains three morphologically different receptor cell types: ciliary receptor cells, microvillous receptor cells, and receptors with a single rodshaped free appendage. The ciliary receptors have 4 to 8 “sensory” cilia which project from below the vesicula olfactoria, each forming a constant angle of about 30° with the vertical cell axis. The vesicula olfactoria of the microvillous receptors bears from 30 to 60 microvilli, each of 0.1 μm diameter and up to 5 μm length. Each microvillus of this receptor type contains a central tubulus of 160 Å diameter. Few centrioles are located closely to the vesicula olfactoria. The third receptor type, which has neither cilia nor microvilli, is characterised by a single rod-shaped appendage of 0.8 μm diameter which projects up to 4 μm above the epithelial surface. This appendage contains neurotubules and fibril bundles; some centrioles lie close to the base of the appendage.
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  • 93
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    Cell & tissue research 125 (1972), S. 277-288 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Exocytosis ; Freeze-etching ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes of rats subjected to severe acute haemorrhage under sodium pentobarbitone anaesthesia were examined electron microscopically and the ultrastructure compared with that in anaesthetised and unanaesthetised controls. Changes in the localisation and numerical distribution of elementary granules and small vesicles in the neurohypophysial nerve endings of bled rats were consistent with the occurrence of exocytosis. The occurrence of “exocytotic profiles” was observed more frequently in freeze-etched tissue samples as compared with the material fixed for conventional electron microscopy. The ratio of small vesicles: elementary granules was shown to be significantly increased (P〈0.005) in the nerve endings of neural lobes from bled rats. Equally, the numbers of exocytotic profiles related to 1000 μm2 of neurohypophysial tissue area were significantly greater (P〈0.005) in bled rats.
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  • 94
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    Cell & tissue research 125 (1972), S. 252-276 
    ISSN: 1432-0878
    Keywords: Amnion-Umbilical-cord-Skin ; Sheep ; Differentiation of the epithelia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Ektoblastderivate Amnion-, Nabelstrang- und Hautepithel von 14 Schaffeten zwischen 1,1 und 44 cm SSL wurden elektronenmikroskopisch untersucht. Das Amnionepithel ähnelt dem anderer Säuger; die tonofibrillenreichen Zellen sind mit Mikrovilli besetzt, seitlich sind sie stark miteinander verzapft. Das Schlußleistennetz bleibt bis zur Geburt erhalten. Der Golgiapparat ist kräftig entwickelt. Glatte Mikropinozytosevesikel von 600–800 Å Ø am basalen und seitlichen Plasmalemm werden mit fortschreitender Entwicklung zahlreicher. Größere Vakuolen fehlen. Das Nabelstrangepithel bleibt im Gegensatz zu anderen Spezies ein geringfügig modifiziertes Amnionepithel ohne eigene Differenzierung. In der zweiten Trächtigkeitshälfte sind die Interzellularräume durchschnittlich weiter als im peripheren Amnionepithel. Mikropinozytosebläschen kommen auch an apikalen Mikrovilli vor. Die Epidermis ist schon im einschichtigen Stadium nicht amnionähnlich, die apikalen Mikrovilli sind wesentlich spärlicher und kürzer, die Interzellularräume sind oft einfacher geformt, basal finden sich bereits Hemidesmosomen. Bei größeren Feten werden die Interzellularräume sehr eng, die Mikrovilli stehen in Gruppen. Weder in den glykogenbeladenen Peridermzellen noch in den Basalzellen sind Pinozytosevesikel, Fruchtwasservakuolen oder andere Indizien für einen Fruchtwassertransport zu finden.
    Notes: Summary The ultrastructure of the derivates of the ectoblast, the epithelia of the amnion, umbilical cord and skin has been studied in fetal sheep ranging from 1.1 to 44 cm CRL. The amniotic epithelium is similar to that of other mammals. The cells are rich in tonofilaments, they carry microvilli and are interdigitated with one another. Terminal bars are retained until birth. The Golgi apparatus is well developed. Smooth micropinocytotic vesicles with a diameter of 600–800 Å on the basal and intercellular cell membranes become more numerous with progressing development. Larger vacuoles are missing. The epithelium of the umbilical cord, contrary to that of other species, remains a slightly modified amniotic epithelium without special differentiation. The intercellular spaces are on the average wider in the second half of pregnancy than those in the peripheral amniotic epithelium. Micropinocytotic vesicles occur also on the apical microvilli. In the single layer stage the epidermis is dissimilar to that of the amniotic epithelium. The apical microvilli are far less numerous and shorter, the intercellular spaces are often of a more simple structure. Hemidesmosomes occur in the basal cell membrane. Later the intercellular spaces become very narrow, the microvilli are present in clusters. Pinocytotic vesicles, amniotic fluid vacuoles or other indications of amniotic fluid transport are to be found neither in the glycogen-rich peridermal cells, nor in the basal cells.
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  • 95
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    Cell & tissue research 125 (1972), S. 289-294 
    ISSN: 1432-0878
    Keywords: Accessory optic system ; Rat ; Blood vessels ; Extracellular space ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of capillaries were found in the medial terminal nucleus of the rat accessory optic system. Type one capillaries are surrounded by glial processes and lack a perivascular space, whereas the type two capillaries and arterioles show a distinct extracellular perivascular space often filled with collagen fibrils. An internal as well as an external basal lamina lines these spaces. No fenestration of the endothelium was observed.
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  • 96
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    Cell & tissue research 125 (1972), S. 415-431 
    ISSN: 1432-0878
    Keywords: Synapses ; Rat ; Cerebral cortex ; Glutaraldehyde/E-PTA ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synaptic junctions in intact rat cerebral cortex have been examined following glutaraldehyde fixation and phosphotungstic acid (PTA) staining. In the presynaptic ending the network has a hexagonal arrangement, while the dense projections are regularly placed along the presynaptic membrane. Cleft densities occupy the intracleft region. The postsynaptic thickening extends uninterrupted along the length of the junction. Qualitatively, the majority of junctions fall into the ‘discontinuous-continuous’ category, in which the internal coat of the presynaptic membrane together with its associated dense projections is discontinuous along the length of the junction, whereas the postsynaptic thickening is continuous. By contrast, a small number of junctions are ‘continuous-continuous’. In an attempt to analyze the junctions quantitatively, nine indices were measured. Histograms of the size distributions of seven of these appear to be bimodal, and from this it is concluded that two junction populations may be distinguishable on quantitative grounds. It is also shown that the distance separating dense projections at the presynaptic membrane is of the order of 10–15 nm. This surprisingly low value has consequences for current ideas on the relationship between synaptic vesicles and dense projections, and these are discussed at length.
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  • 97
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    Cell & tissue research 125 (1972), S. 404-414 
    ISSN: 1432-0878
    Keywords: Renal medulla ; Rat ; Interstitial ground substance ; Fixation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Interstitium des inneren Nierenmarkes von Ratten wurde nach Anwendung verschiedener Fixierungsarten und Versuchsanordnungen elektronenmikroskopisch untersucht. Neben Bindegewebszellen und kollagenen Fibrillen enthält der interstitielle Raum bandförmige, basalmembranartige Strukturen, in deren weiträumigen Maschen zwei weitere Komponenten, nämlich ein feingranuläres und feinfilamentäres Material sowie kontrastreiche, globuläre Partikel liegen. Diese beiden Formelemente stellen sich bei den verschiedenen Fixierungsarten und Versuchsanordnungen unterschiedlich dar. Bei der feingranulären und feinfilamentären Komponente handelt es sich wahrscheinlich um interstitielles Blutplasma. Diese Deutung wird gestützt durch die morphologische Ähnlichkeit mit dem Blutplasma der Blutgefäße, die unterschiedliche Darstellbarkeit nach Glutardialdehyd-und Formalinfixierung sowie durch die Befunde nach Gefäßperfusion und Nierenvenenstauung. Das Verhalten der globulären Partikel nach OsO4-Einwirkung steht in Einklang mit der schon früher gegebenen Interpretation als präzipitierte saure Mukopolysaccharide. Ihr elektronenoptisches Bild wird im Vergleich zur bekannten makromolekularen Struktur der Mukopolysaccharid-Protein-Moleküle diskutiert.
    Notes: Summary The interstitial ground substance in the inner medulla of the rat kidney is examined electron microscopically after fixation with various fixation agents and under different experimental conditions. The papillary interstitium contains besides interstitial cells and few collagen fibrils basement membrane like material and two other components, fine granular-fibrillar elements and globular particles with heavy contrast. The appearance of the two latter interstitial components varies according to the different fixation agents used and to the experimental conditions. The fine granular and fine fibrillar material surrounds the globular particles numerously after glutardialdehyde-fixation but scarcely after formaldehyde-fixation. It increases after renal vein occlusion, but is diminished or absent, if the kidney is rinsed bloodfree. These results allow to conclude that this material represents interstitial bloodplasma. The behaviour of the globular particles after OsO4-fixation agrees well with the earlier interpretation according to which they represent precipitated acid mucopolysaccharides. Their electron microscopic appearance is discussed in comparison with the known macromolecular structure of the acid mucopolysaccharides.
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  • 98
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    Cell & tissue research 125 (1972), S. 432-447 
    ISSN: 1432-0878
    Keywords: Synaptosomes ; Synapses ; Rat ; Cerebral cortex ; Glutaraldehyde/E-PTA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Working with glutaraldehyde fixed, PTA stained rat cerebral cortex, the authors compared the ultrastructural features of synaptosomes with those of intact synaptic junctions. In general there is close correspondence between the two, although the cleft densities and postsynaptic focal densities of synaptosomes show a greater degree of focalization than their counterparts in synaptic junctions. The dense projections have similar profiles in both preparations, but are more difficult to distinguish clearly in synaptosomes on account of the closer packing of the presynaptic network around their apices. The limiting membrane of the presynaptic terminal is usually visible in synaptosomes, but not in synaptic junctions. Comparing the preparations quantitatively reinforces the qualitative findings, and points to their overall similarity. However a number of the indices in synaptosomes are significantly smaller than the corresponding ones in synaptic junctions, and this points to the operation of a shrinkage factor during fractionation procedures. This is confined to the pre- and post-synaptic components and does not affect the intervening contact region. Histograms of the size distributions of the indices are similar to those obtained for intact synaptic junctions, the majority displaying two peaks. It is concluded that synaptosomes accurately reproduce the major ultrastructural features of synaptic junctions.
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  • 99
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    Cell & tissue research 125 (1972), S. 480-496 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Normal ; Hypophysectomy ; Structural alteration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adrenal cortex of normal and hypophysectomized rats was observed by electron microscopy 5–90 days after the operation and, chiefly, the degeneration mechanism of the cortical tissue was discussed. In normal rats mitochondrial inner structures are generally tubular in shape in glomerulosa cells, vesicular (and tubulo-vesicular) in fasciculate cells and tubulo-vesicular (and vesicular) in reticularis cells. Some mitochondria in a few glomerulosa cells show long straight tubular crests in normal as well as hypophysectomized rats. Usually lipid droplets in normal glomerulosa, fasciculate and reticularis cells are surrounded by elements of smooth endoplasmic reticulum, which are very closely associated with mitochondria. About 10–25 days after hypophysectomy, most mitochondria in fasciculate and reticularis cells show tubular crests, and numerous electron lucent lipid droplets are accumulated in these cells. These droplets occupy most parts of the cytoplasm and are sometimes in contact with one another or with mitochondria. The elements of smooth endoplasmic reticulum and Golgi apparatus are markedly reduced in number and size. About 10–90 days after the hypophysectomy, the degenerative cortical cells containing irregularly shaped nuclei, heterogeneously dense bodies in various sizes, and a large number of electron lucent lipid droplets are seen. The author speculates that most fasciculate and reticularis cells degenerate because of a disorder in the lipid metabolism, since ACTH release, which is necessary for synthesis of corticosteroid hormones from cholesterol, is absent in hypophysectomy. The fatty degeneration of the fasciculate and reticularis cells is considered to be a main cause for attenuation of the cortical tissue. Sometimes atrophied cortical cells without lipid droplets are also found 60–90 days after hypophysectomy.
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  • 100
    ISSN: 1432-0878
    Keywords: Hypophyse ; Quail ; Thyroidectomy ; Castration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé On compare l'ultrastructure et la localisation des phosphatases acides au niveau des cellules hypophysaires delta et beta, chez des Cailles mâles thyroïdectomisées et maintenues en photopériode courte ou bien castrées, puis placées en photopériode longue. On étudie en outre, dans ces deux cas, les effets d'injections de doses croissantes de thyroxine. La thyroïdectomie provoque la transformation des cellules delta en cellules de thyroïdectomie groupées en îlots à la périphérie du lobe céphalique. Ces cellules sont pauvres en phosphatases acides. La thyroxine (10 μg/j pendant 2 jours) provoque la régression de ces cellules et l'apparition de lysosomes. Les cellules beta ne sont pas modifiées par la thyroïdectomie. La castration-photostimulation stimule les cellules beta localisées dans le lobe céphalique. Elle provoque dans les deux lobes de la glande l'hypertrophie et la vacuolisation des cellules delta qui se distinguent des cellules de thyroïdectomie par la présence de nombreux lysosomes. La thyroxine freine simultanément l'activation des cellules delta et des cellules beta, en provoquant la formation de lysosomes, mais la dose efficace chez le mâle photostimulé (20 μg et 60 μg/j pendant 5 jours) est sans effet chez le castrat photostimulé (dose efficace 180 μg/j). Pour interpréter ces faits, on admet que les cellules delta, thyréotropes et les cellules beta, gonadotropes, seraient simultanément soumises à un contrôle freinateur des hormones thyroïdiennes et des stéroïdes mâles.
    Notes: Summary The ultrastructure and the localization of acid-phosphatase activity are compared in beta and delta pituitary cells of male Japanese quail, either thyroidectomized and maintained in short days, or castrated then put in long days. Moreover, in these two cases, the effects of brief treatments with increasing doses of thyroxine are studied. Thyroidectomy induces transformation of delta cells into “thyroidectomy cells” arranged in clumps at the periphery of the cephalic lobe. The acid-phosphatase activity of such cells is low. Thyroxine (10 μg per day for two days) causes regression of these cells and the appearance of numerous lysosomes. Beta cells are not modified by thyroidectomy. Castration and exposure to long days stimulate beta cells, localized in the cephalic lobe. It induces, also, in both pituitary lobes, hypertrophy and vacuolization of delta cells which differ from thyroidectomy cells by the presence of numerous lysosomes. Thyroxine in photostimulated quail inhibits both delta- and beta-cell stimulation and increases the frequency of lysosomes but the effective doses on males (20 μg or 60 μg per day for five days) are inactive on castrates, the response of which is obtained with 180 μg per day. In order to explain these data, a hypothesis is suggested: Thyrotropic delta cells and gonadotropic beta cells are both subject to a double inhibiting control by thyroid hormones and male steroids.
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