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  • 1970-1974  (3,155)
  • Life and Medical Sciences  (2,378)
  • Engineering General  (489)
  • Rat  (288)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 145 (1974), S. 169-186 
    ISSN: 1432-0568
    Keywords: Renal innervation ; Rat ; Peripheral nerves ; Neuroeffector zones ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der Rattenniere werden die muskelzellhaltigen arteriellen Gefäße und der juxtaglomeruläre Apparat innerviert. Blutgefäße mit Pericyten, porenhaltige Capillaren sowie die Tubuli der Rinde und des Markes werden nicht von Nervenfasern begleitet. Ganglienzellen wurden in der Rattenniere nicht beobachtet. Periphere Nerven mit einem ein-bis zweischichtigen Perineurium kommen im paravasalen Gewebe der Interlobar- und Arcuata-Arterien vor; sie enthalten neben zahlreichen marklosen Nervenfasern gewöhnlich auch 2–4 markhaltige. Nervenfaser-Bündel ohne perineurale Scheide finden sich im paravasalen Gewebe der Arcuata- und Interlobular-Arterien. Darüber hinaus sind in unmittelbarer Nachbarschaft der großen Arterien (Interlobar-, Arcuata- und Inter-lobular-arterien) und der Vasa afferentia marklose Nervenfasern und freie Axone vorhanden, die auch die proximalen Abschnitte der Vasa efferentia der subcapsulären und intermediären Rindenschicht begleiten. Im Nierenmark werden die juxtamedullären Vasa efferentia und die Arteriolae rectae innerviert; marklose Nervenfasern und freie Axone sind nur bis zur Außen-Innenstreifen-Grenze nachweisbar. Die Innervation der muskelzellhaltigen arteriellen Gefäße erfolgt durch aufgetriebene Axonabschnitte (Neuroeffektor-Zonen), die vorwiegend agranuläre Vesikel enthalten. Diese Strukturen liegen stets an der Grenze von Adventitia und Media bzw. Elastica externa; zwischen den glatten Muskelzellender Media wurden keine vesikelhaltigen Axonabschnitte gefunden. Als minimaler Abstand zwischen den vesikelhaltigen Axonabschnitten und den von einer Basalmembran umschlossenen glatten Muskelzellen (neuromuskuläre Distanz) wurden 600 Å gemessen. Die vorliegenden Ergebnisse werden mit den fluoreszenzmikroskopischen und histochemischen Untersuchungen über die adrenerge und cholinerge Innervation der Niere verglichen. Die sich aus diesem Vergleich ergebenden Probleme und funktionellen Konsequenzen für die Innervation der Niere sowie die Natur der cholinergen Fasern (afferente oder postganglionäre parasympathische Fasern) werden diskutiert.
    Notes: Summary The innervation of the rat kidney is defined by a system which supplies those arterial blood vessels whose walls contain smooth muscle cells and the juxtaglomerular apparatus. Vessels containing pericytes, or those vessels composed of an endothelium only, as well as the tubules of both the cortex and medulla, are not innervated. Furthermore, ganglion cells do not occur in the rat kidney. The nervous apparatus of the rat kidney consists of peripheral vegetative nerves, ensheathed by a perineurium, with 2–4 myelinated fibers running in the paravasal tissue of the interlobar and arcuate arteries, and of nerve bundles without a perineurial sheath in the paravasal tissue of the arcuate and interlobular arteries. Non-myelinated fibers and free axons occur in the immediate vicinity of the great arteries (interlobar, arcuate, and interlobular) and the vasa afferentia. Nerve fibers and free axons are also seen in the vicinity of only the proximal parts of those vasa efferentia which supply the cortical capillary plexus. The arteriolae rectae of the medulla, and their vasa efferentia, from which they arise, are innervated by non-myelinated fibers and free axons which accompany these arterial vessels only to the boundary of the outer and inner stripe of the outer zone of the medulla. The functional innervation of those vessels with smooth muscle cells results from neuro-effector zones which predominantly show agranular vesicles. These structures were never seen between the smooth muscle cells within the media; the minimum neuromuscular distance was 600 Å. The present findings are correlated with the lightmicroscopically demonstrated adrenergic and cholinergic innervation. The resultant problems and functional consequences of the innervation of the kidney, especially the nature of the cholinergic fibers (afferent or post-ganglionic parasympathetic fibers) are briefly discussed.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 145 (1974), S. 223-226 
    ISSN: 1432-0568
    Keywords: Rat ; Liver ; Bile ducts ; Cilia ; Scanning Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Numerous cilia have been demonstrated by SEM in cells of rat perilobular and portal bile ducts and ductules. Generally these cilia appear as long, cylindrical evaginations of the plasma membrane. Some of them are so long that, curving and twisting at many points, they cross the ductal lumen. It has been suggested that they may be related to a continual mixing up and propulsion of the bile product down the biliary tree.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 143 (1974), S. 215-222 
    ISSN: 1432-0568
    Keywords: Lung ; Stretch receptors ; Light microscopy ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Lappenbronchien (3./6.) (Durchmesser bei mittlerer Inspirationslage 500–700 μ) von männlichen und weiblichen Wistarratten wurden licht- und elektronenmikroskopisch untersucht. Diese Bronchien entsprechen im Wandbau den mittleren Bronchioli größerer Säugetiere. Freie, verzweigte lanzettförmige Terminalfasern werden im Bindegewebe der lamina propria beschrieben. Sie sind in das elastisch muskuläre System der Bronchuswand eingebaut. Die zugehörige markhaltige afferente Nervenfaser ist verzweigt und hat einen Durchmesser von 4–6 μ. Außerdem werden efferente motorische Endigungen an der glatten Bronchialmuskulatur beschrieben. Die freien lanzettförmigen und verzweigten Terminalfasern sind möglicherweise Dehnungsrezeptoren für den Hering Breuer Reflex.
    Notes: Summary In rats the 3rd to 6th bronchi, measuring 500–700 μ in diameter during inspiration, were investigated by light and electron microscopy. The histological appearance of these bronchi is comparable to that of medium sized bronchioles of larger animals. The branched and lanceolate terminals are associated with the connective tissue of the lamina propria and the smooth muscle cell layer. In this way the terminals are bound to the myoelastic system of the bronchial wall. The myelinated afferent fiber is branched and the diameter measures about 4–6 microns. Besides afferent nerve terminals these are numerous efferent endings on the smooth muscle basement laminae. It is supposed that the described receptor represents the pulmonary stretch receptor of the Hering Breuer reflex.
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  • 4
    ISSN: 1432-0568
    Keywords: Superior cervical ganglion ; Rat ; p-Chlorophenylalanine ; 5-Hydroxytryptamine ; Catecholamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Wirkung von Parachlorophenylalanin (pCPA) auf die paraganglionären Zellen und sympathischen Ganglienzellen des Ganglion cervicale superius der Ratte wurde untersucht. pCPA beeinflußt die sympathischen Nervenzellen im Ganglion cervicale superius geringgradig. Es finden sich unspezifische Veränderungen des Golgi-Apparates und der Nissl-Schollen sowie eine Zunahme von Lysosomen. Bei langdauernder Behandlung degenerieren einzelne Ganglienzellen und Nervenfasern. Die paraganglionären Zellen sind bei Kontrolltieren durch “dense core vesicles” eines einheitlichen Typs charakterisiert. Im Laufe der pCPA-Behandlung finden sich degranulierte paraganglionäre Zellen. Die Degranulation der einzelnen Zellelemente ist jedoch variabel. Bei fluorescenzmikroskopischer Untersuchung zeigt sich nach pCPA-Applikation eine Verschiebung des Fluorescenzspektrums zum grünen Bereich hin. Die bei Kontrollen deutliche Gelbkomponente nimmt nach 6–12 Tagen ab und verschwindet schließlich nach 18–20 Tagen. Es wird diskutiert, ob die fluorescenzmikroskopischen Veränderungen aufgrund einer Hemmung der Serotoninsynthese oder aufgrund einer abgeschwächten Katecholaminsynthese entstehen.
    Notes: Summary The effect of parachlorophenylalanine (pCPA) on the paraganglionic and sympathetic nerve cells of the rat superior cervical ganglion was studied. pCPA influences the sympathetic nerve cells of the cervical ganglion to minimal extent. Unspecific changes of the Golgi apparatus and of the Nissl bodies as well as an increase in the number of lysosomes occur. An extended period of treatment causes degeneration of individual ganglionic cells and nerve fibers. The paraganglionic cells in control animals are characterized by dense core vesicles of an unitary type. During pCPA treatment degranulated paraganglionic cells are to be found. The degranulation of the individual cell elements varies. Fluorescence microscopic study after pCPA application shows a shift of the fluorescence spectrum toward green. The yellow component of the control group decreases after 6 to 12 days and disappears after 18 or 20 days. It is discussed whether the fluorescence microscopic changes are due to the inhibition of serotonine synthesis or to a decrease of the catecholamine synthesis.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 144 (1974), S. 173-186 
    ISSN: 1432-0568
    Keywords: Hippocampus ; Neurogenesis ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summay The prenatal ontogeny of the hippocampus, including the anterior continuation and induseum griseum, was examined in the rat by means of tritiated thymidine autoradiography. The neurons of the anterior continuation formed between the 16th and 18th days of embryonic development. The neurons of the induseum griseum were formed on the 16th and 17th days of gestation. The pyramidal cells of ammon's horn were formed during the 16th, 17th, 18th, and 19th days of embryogenesis but were preceded by the large interneurons of the stratum lacunosum-moleculare which formed on days 15 and 16 of embryonic life. The granule cells of the superficial layers of the stratum granulosum formed during the 20th, 21st, and 22nd days of gestation.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 143 (1974), S. 185-203 
    ISSN: 1432-0568
    Keywords: Basement membrane labyrinths ; Cerebral ventricles ; Development ; Rat ; Light and Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Gehirne embryonaler und neugeborener Ratten wurden im Hinblick auf die frühe Entstehung der Basalmembranlabyrinthe licht- und elektronenmikroskopisch untersucht. 1. An den Hirngefäßen embryonaler Ratten der 2. und 3. Fetalwoche kommen zwar bereits Basalmembranen vor, sub- oder interependymale Basalmembranlabyrinthe fehlen aber noch. 2. Basalmembranlabyrinthe werden mit der Perjodsäure-Bisulfit-Aldehydthionin-Methode lichtmikroskopisch ab dem 20. Tag an umschriebenen Stellen des Ventrikelsystems gefunden; elektronenmikroskopisch treten die ersten Basalmembranlabyrinthe am 12. postnatalen Tag auf. 3. Die ersten interependymalen Labyrinthe erscheinen in Erweiterung der interependymalen Spalten in der Nähe von ausgedehnten Golgifeldern. Der Labyrinthinhalt besteht aus einer feinflockigen Substanz. Diese liegt wolkenartig angehäuft gegenüber bogenförmigen Ausbuchtungen lokal verbreiterter Zellmembranen. In Ausbildung begriffene Labyrinthe zeigen eine lamelläre Gliederung. 4. Ab dem 12. postnatalen Tag treten auch an den Basalmembranen der pericapillären Zellen, in denen lichtmikroskopisch Glykoproteide nachweisbar sind, zapfenartige Duplikaturen auf. Die Zapfen sind überwiegend ependymwärts gerichtet. Verbindungen zwischen den Basalmembranzapfen und den interependymalen Basalmembranlabyrinthen werden in den ersten 30 Lebenstagen nicht gefunden. 5. Sowohl an den die interependymalen Labyrinthe begrenzenden Plasmalemmata als auch am Plasmalemm der pericapillären Zellen fallen Stachelsaumbläschen auf, deren Membran in die Zellwand eingebaut wird. Ihr Inhalt scheint in die entstehenden Labyrinthe entleert zu werden. 6. Da sich an den tubulären Enden der Doppellamellen der Dictyosomen Strukturen befinden, die den Stachelsaumbläschen morphologisch gleichen, und da im Bereich des Golgifeldes und im Cytoplasma zwischen diesem und der Zellwand zahlreiche Stachelsaumbläschen liegen, wird angenommen, daß das Material der Basalmembranlabyrinthe dem Golgiapparat entstammt und vermittels der Stachelsaumbläschen zur Zellwand transportiert wird. Bogenförmige Ausbuchtungen lokal verbreiterter Zellmembranen im Bereich entstehender Labyrinthe werden als Reste von Stachelsaumbläschen aufgefaßt, deren Membran in die Zellwand eingebaut wurde. 7. Da die phylogenetische Zunahme des Hirnmantels mit einem Verlust der langen in das Gehirn reichenden basalen Ependymfortsätze an den größten Teilen der Ventrikelwand einhergeht und niedere Tiere noch nicht über Basalmenbranlabyrinthe verfügen, wird angenommen, daß diese die Transportfunktion für Stoffe aus dem Liquor übernommen haben, die vordem nach allgemeiner Auffassung über die langen Fortsätze in das Gehirn gelangten.
    Notes: Summary The brains of embryonic and new-born rats were investigated by means of light- and electron microscopy with regard to the early formation of basement membrane labyrinths. 1. Though basement membranes are already found around the brain capillaries of embryonic rats from the 2nd week of pregnancy, sub- and interependymal basement membrane labyrinths are still absent. 2. Basement membrane labyrinths, being demonstrable for light microscopy by a periodicacid-bisulfite-aldehydethionin-method, appear around the 20th day after birth at certain places of the ventricular system. By means of electron microscopy, basement membrane labyrinths have first been detected at the 12th postnatal day. 3. The earliest interependymal basement membrane labyrinths are found in enlargements of the interependymal spaces near a distended Golgi apparatus. The contents of the labyrinths, being composed of a loose flocculent material, are of a lamellar structure. In the intercellular space the material is situated opposite bow-shaped excavations of local broadenings of cell membranes. 4. From the 12th postnatal day, plug-like duplications of basement membranes occur at the ependymal side of the pericapillar cells, which contain glycoproteids. The plugs of basement membranes are directed towards the ependymal layer. No connections between the interependymal basement membrane labyrinths and the plugs of pericapillary basement membranes exist within the first 30 days of life. 5. At the plasmalemma of ependymal cells bordering the interependymal labyrinths, and at the cell membrane of pericapillary cells, coated vesicles are to be found, which are fused with the cell membrane. The contents of these vesicles seem to be released into the developing labyrinths. 6. At the tubular ends of dictyosomes, coated vesicle-like structures can be demonstrated. In the environment of the Golgi apparatus many coated vesicles are situated; they can even be found between the Golgi apparatus and the walls of labyrinthś. Therefore the coated vesicles are considered to be transport vesicles, transporting the material which is formed in the Golgi apparatus towards the cell membrane. 7. Since the phylogenetic increase of the brain mantle is accompanied by loss of the long processes of ependymal cells that reach far into the brain, and since lower animals have no basement membrane labyrinths, it is suggested that the basement membrane labyrinths have a transport functions for material from the cerebrospinal fluid which in lower animals is assumed to be transported by the long processes of ependymal cells.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 143 (1974), S. 255-262 
    ISSN: 1432-0568
    Keywords: Median eminence ; Neuro-vascular contacts ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The vascular surface of the external layer of the median eminence is composed of neuronal and glial processes. Neuro-vascular contacts are supposed to be necessary for the release of hypophysiotropic neurohormones. The present study confirms the hypothesis that the relative extent of neuro-vascular and glio-vascular contacts varies under different functional conditions of the tubero-hypophysial system. Morphometric analysis shows that in normal rats about 20% of the surface is lined by neuro-vascular contacts. After bilateral adrenalectomy the neuro-vascular contacts are enlarged to 40% whereas application of an extract of stalk-median eminence tissue is followed by a decrease of the neuro-vascular contacts to 15%. The implications of these results are discussed.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 144 (1974), S. 101-122 
    ISSN: 1432-0568
    Keywords: Subcommissural organ ; Periodically structured bodies ; Vascular permeability ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Capillaren des Subcommissuralorgans (SCO) und deren Umgebung wurden an 38 adulten Sprague-Dawley- und an 6 adulten Wistar-Ratten nach Perfusionsfixierung im Elektronenmikroskop untersucht. Saure Mucopolysaccharide wurden mit Alcianblau und Rutheniumrot, Glykoproteide mittels der Perjodsäure-Silbermethenamin-Reaktion nachgewiesen. Der Stofftransport in den Capillaren wurde mit Meerrettichperoxidase (MRP) als Tracer untersucht. Die subcommissuralen Capillaren besitzen ein ungefenstertes, vesikelarmes Endothel, das einer einfachen, durchgehenden Basallamina aufsitzt. In der Umgebung der Capillaren finden sich neben periodisch strukturierten Körpern (PSK) vereinzelt Basallamina-Labyrinthe und regellos angeordnete kollagene Mikrofibrillen. Mit der Perjodsäure-Silbermethenamin-Reaktion lassen sich Glykoproteide im Bereich der Basallamina und der nach außen anschließenden Intercellularspalten darstellen, vereinzelt auch — teils im Bereich der Basallamina, teils ihr eng angeschlossen — Gruppen parallel angeordneter, linearer Strukturen mit einem periodischen Streifenmuster. Saure Mucopolysaccharide sind nur in der lumenseitigen Glykokalyx des Capillarendothels nachweisbar. Der Aufbau der PSK aus Kollagenfilamenten erscheint sehr wahrscheinlich. Vermutungen zur Entstehung dieser hochgeordneten Strukturen werden vorgebracht. Die Traceruntersuchungen ergeben, daß unter normalen Bedingungen in den subcommissuralen Capillaren eine Blut-Hirn-Schranke (BHS) für MRP besteht, die im Endothel lokalisiert ist. Bei einem Teil der Sprague-Dawley-Ratten ist die Barriere geschädigt und der Tracer gelangt über cytopemptische Vesikel in Basallamina und Gefäßumgebung. Der Basallamina und den PSK kommt in solchen Fällen keine besondere Schranken- oder Verteilerfunktion zu. Offenbar bewirkt bei manchen Sprague-Dawley-Ratten die MRP-Injektion über die Freisetzung von endogenen biogenen Aminen aus Mastzellen eine Schädigung der BHS, was bei Wistar-Ratten nicht eintritt.
    Notes: Summary The capillaries of the subcommissural organ (SCO) and their adjacent structures of 38 adult Sprague-Dawley rats and 6 adult Wistar rats were examined in the electron microscope after perfusion fixation. Acid mucopolysaccharides were shown by Alcian Blue and Ruthenium Red, glycoproteins were identified by the periodic acid-silver methenamine technique. Horseradish peroxidase (MRP) was used as a tracer for vascular permeability. The subcommissural organ's capillaries are characterized by an unfenestrated, continuous endothelium, showing only few vesicles; the endothelium is surrounded by a single, continuous basal lamina. Adjacent to the capillaries wall there are “periodically structured bodies” (PSK), labyrinths of the basal lamina and irregularly arranged collagen fibrils. Glycoproteins are found in the basal lamina and within the intercellular clefts; in a few cases groups of parallel arranged, periodically banded linear structures are seen within or adjacent to the basal lamina. Acid mucopolysaccharides are found within the endocapillary layer of capillaries. It seems very likely that PSK represent an atypical arrangement of collagen fibrils. The formation of these structures is discussed. Under normal conditions, MRP, after intravenous injection, does not enter the perivascular space surrounding the capillaries of the SCO. A blood-brain barrier exists at the level of the capillary endothelium. In a few Sprague-Dawley rats MRP seems to alter the permeability of the capillaries. Reaction product of MRP is found within endothelial vesicles and the adjacent structures. It appears that the basal lamina and the PSK are not involved in the barrier mechanism or regulation of transport. In Sprague-Dawley rats intravenous injection of MRP seems to alter the blood-brain barrier by release of endogenous biogenic amines associated with mast cell degranulation. This effect is not observed in Wistar rats.
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  • 9
    ISSN: 1432-0568
    Keywords: Motor nerve terminals ; Methylene blue stain ; Hindlimb muscles ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary With methylene blue stain, three morphological types of motor nerve terminals were distinguished in hindlimb muscles (extensor digitorum longus, semitendinosus, soleus, and tibialis anterior muscles) of rat. Type A terminals possess many long thin branches with numerous minute swellings, type C ones possess few and thick terminal branches with few large swellings, and type B ones possess intermediate characteristics. The frequencies of occurrence of these types are characteristic for each muscle and differ between different hindlimb muscles. Specifically, soleus muscle contains a much higher proportion of type B terminals than other hindlimb muscles, and the superficial part of tibialis anterior muscle contains a higher proportion of type A terminals and a lower proportion of type C ones than the deep part. The frequencies of occurrence of types A, B, and C terminals closely parallel the frequencies of “white”, “intermediate”, and “red” muscle fibers (as determined by a fat stain), respectively, in the different muscles. As also suggested previously for the diaphragm, it is concluded that three morphological types of motor nerve terminals each may innervate one of three types of muscle fibers.
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  • 10
    ISSN: 1432-0568
    Keywords: Pantothenic acid deficiency ; Corticotropin-releasing factor ; Corticoids ; Histologie ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the outer layer of the rat median eminence “Gomori-positive” granules occur which are assumed to be the morphological correlate of the corticotropin-releasing factor (CRF). The present study was carried out in order to establish whether the amount of these CRF-granules is influenced by a pantothenic acid (PA)-deficiency, which is known to result in an inhibition of corticosteroid production. Female SPF Wistar rats were used. PA-deficiency was induced by PA-free nutrition and/or administration of the PA-antagonist Ω-methyl-PA. Corresponding experimental groups were given either tap water or a solution of 1% NaCl and 5% glucose in tap water to drink. In rats fed with a diet free of PA and in addition treated with Ω-methyl-PA a severe disturbance of the corticoid balance developed within 6 weeks. The corticosterone production was depressed to about 11–16% of the control values. The adrenal cortex showed necrotic changes which either involved the whole parenchyma or were confined to the inner zones. In those animals in which a subcapsular region, in its extent corresponding to the zona glomerulosa, remained intact, an augmentation of the CRF-granules was observed. In those animals, however, in which the whole adrenal cortex was damaged, the amount of CRF-granules did not increase. Administration of the 1% NaCl containing drinking fluid did not influence the augmentation of the CRF granules, but had a protective effect on the development of necrotic changes in the zona glomerulosa of the adrenal cortex. The findings show that a functional relationship exists between the inner zones of the adrenal cortex and the CRF-granules in the median eminence.
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  • 11
    ISSN: 1432-0568
    Keywords: Neurohypophysis ; Neuro-vascular contacts ; Neuro-glial synaptoid contacts ; Dehydration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The posterior lobe of the hypophysis consists of neurosecretory nerve fibres and glial cells, both abutting on the perivascular space of sinusoidal capillaries. Nerve fiberes and glial cells are connected with each other by a high number of synaptoid contacts. Several ultrastructural changes following dehydration have been described by other authors. This study presents the data of some morphometric investigations on normal and dehydrated rats. The relative extent of neuro-vascular contacts is not contstant; it increases significantly from 52 (±2.8)% in normal rats to 67(±1.2)% in rats with a dehydration time of 3 days. Correspondingly the extent of glio-vascular contacts is diminished. In addition, water-deprived animals show a clear increase in the number of neuro-glial synaptoid contacts with 3.1 (±0.4) per square unit nervous tissue compared to 2.1 (±0.3) per Square unit in untreated controls. These results indicate a dynamic motility of neuronal and glial elements depending on functional conditions, as was found for the external layer of the median eminence. Furthermore there seems to be a relationship between secretory activity and the number of neuroglial synaptoid contacts.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 28 (1974), S. 25-35 
    ISSN: 1432-0533
    Keywords: Chronic Lead Intoxication ; Rat ; Ultrastructure ; Microglia ; Pericytes ; Monocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Wistar rats of both sexes and the same litter were exposed to chronic lead intoxication from birth untill sacrifice 9 months later. Lead was administered as 0.4% solution of lead nitrate in drinking water. Samples from the parietal brain cortex were examined electron microscopically following intracardiac perfusion with paraformaldehyde-glutaraldehyde solution. Similar changes were observed in the microglial cells and the vascular pericytes whereas all the other tissue elements appeared intact. Both cell types hypertrophied, the microglia assumed characteristic spindle or rod shape, the cell organelles increased, the microglial endoplasmic reticulum widened strongly and a large number of lipid inclusions appeared. The latter consisted of large lipid droplets of varying size and shape, containing multiple zones of low density, and a dense component with a coarse granular structure. The similarity in the response of both cell entities to the lesion as well as some probable functions of microglial cells and their relationship to vascular pericytes are discussed.
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  • 13
    ISSN: 1432-0533
    Keywords: Allergic Encephalomyelitis ; Organ Culture ; Brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experimental allergic encephalomyelitis (EAE) developed in 15 of 30 rats injected with a mixture of Freund's adjuvant and homogenized guinea pig brain, and killed after 6–29 days. The incidence and severity of the disease increased with time after inoculation and in 2 animals involvement of the epiphysis, not previously reported in EAE, was detected. Toxic effects on cells in cultured adult rat cerebellar cortical tissue were produced by exposure for 24 h to the sera of rats killed 12–29 days after inoculation either with the antigenic suspension or with adjuvant alone. Severe toxicity to axons (widespread fragmentation) was produced only by the sera of animals injected with antigenic inocula and killed 17–29 days later. Severe axonal toxicity was not, however, correlated with the presence of EAE in the rats from which the sera were taken. It was not possible to assess myelinotoxic effects in the system used. It is suggested that the organ culture technique may detect the presence in the sera of inoculated animals of toxic principles which, owing to the blood-brain barrier, do not normally contribute to the pathogenesis of EAE.
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  • 14
    ISSN: 1432-0533
    Keywords: Cholesterol Inhibitors ; Cerebrum ; Neuronal Inclusions ; Oligodendroglial Degeneration ; Rat ; Abnormal Sterols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Wistar strain of rats received daily intraperitoneal or oral administration of Triparanol, 250 mg per kg of body weight or 20,25-diazacholesterol either 30 mg or 60 mg per kg of body weight starting at the age of 5 days old. Prominent intracytoplasmic osmiophilic inclusions identical to those found in the rats treated with AY9944 (Suzukiet al., 1973) and degeneration of myelin sheaths and oligodendroglia were seen in the myelinating white matter of rats sacrificed after 3, 6, and 9 injections of Triparanol. In diazacholesterol-treated animals, a few identical inclusions were seen in the cortical neurons but only slight changes were seen in oligodendroglia. Biochemical analysis of the brains of the rats receiving Triparanol revealed a large accumulation ofΔ 7,24-cholestadiene-3β-ol and lesser amounts of desmosterol. The brains of the animals treated with diazacholesterol revealed massive accumulation of desmosterol and a minor sterol component, probablyΔ 5,7,24-cholestatriene-3β-ol. Since AY9944, which results in a massive accumulation of 7 dehydrocholesterol (Δ 5,7-cholestadiene-3β-ol) and two other sterols,Δ 7,24-cholestadiene-3β-ol andΔ 5,7,24-cholestatriene-3β-ol, will produce identical neuropathological lesions to those seen in Triparanol treated animals, and since the lesion produced in diazacholesterol treated animals was very slight, there appears to be a correlation between the presence of sterols with a double bond at the 7-position and neuropathological lesions in young rats.
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  • 15
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    Acta neuropathologica 27 (1974), S. 25-32 
    ISSN: 1432-0533
    Keywords: Experimental CNS Tumours ; Nitrosomethylurea ; Ethylnitrosourea ; Primary Cultures ; Tumour Classification ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary By means of the explant technique a series of primary tumours induced by methylnitrosourea (MNU) or ethylnitrosourea (ENU) in the brain of rats were cultured in vitro. The morphology of isomorphic oligodendrogliomas, astrocytomas, glioblastomas and sarcomas under in vitro conditions is described. All these neoplasias show a very distinct morphological picture and growth behaviour, thus permitting their classification. Most of the tumours tend to anaplastic changes during longer cultivation, but in some cases, preferably in well differentiated gliomas, the cytological properties are maintained even during longterm cultivation. The role of anaplasia and intermingling of different neoplastic cell types in experimental tumours are discussed.
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  • 16
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    Experimental brain research 20 (1974), S. 181-192 
    ISSN: 1432-1106
    Keywords: Locus ceruleus ; Cerulo-cortical tract ; Ascending reticular fiber ; Rat ; Fink-Heimer method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to demonstrate the ascending projection from the locus ceruleus by degeneration silver method, the nucleus was destroyed unilaterally in rats and the brains were stained by a modified Fink-Heimer method following various survival times. Additional experiments included the bilateral destruction of the locus ceruleus and the administration of 6-OH-DOPA. For the demonstration of degenerated terminals in the cerebral cortex it is essential to choose an optimal survival time of 4 or 5 days, keep the time of fixation below 1 week, and perform treatments with permanganate and with silver at 37°C. The trajectory and distribution of the cerulo-cortical tract as revealed by the silver degeneration methods is in agreement with the results of the histofluorescence method, with some minor differences. The ascending fibers run through Forel's tegmental fascicle, turn rostro-ventrally to the subthalamus, enter and cross the internal capsule, pass through the ventral part of the caudate-putamen and distribute to the entire cerebral cortex. The tract is mainly ipsilateral, though some fibers are crossing.
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  • 17
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    Experimental brain research 21 (1974), S. 107-112 
    ISSN: 1432-1106
    Keywords: Preoptic units ; Thermosensitivity ; Mean firing rate ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mean firing rates (per 10 sec) of preoptic neurons of the rat were recorded at normal temperature and after central warming and cooling. Thermosensitivity was determined according to the reactions of the mean firing rate. In compatibility with results from other animals we obtained the following percentages (52 neurons): 23% warm-sensitive, 13% cold-sensitive, 64% non-thermosensitive neurons. However, it turned out that a lot of interesting special effects are not taken into account, using exclusively the criterion “increasing/decreasing/constant mean firing rate”. Particularly we observed long lasting adaption processes and stationary non-linear effects as well as striking oscillations which were dependent on the thermal stimuli, while the mean interval value remained constant.
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  • 18
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    Langenbeck's archives of surgery 336 (1974), S. 15-23 
    ISSN: 1435-2451
    Keywords: Rat ; Splenectomy ; Gastric Ulceration ; Increase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An Ratten wurde der Einfluß von Splenektomie auf Magensaftsekretion und Ulcusentstehung untersucht. Sowohl nach “restraint-stress” als auch Pylorusligatur wiesen die splenektomierten Tiere eine ausgeprägte Steigerung der Ulcuszahl und -größe gegenüber den Kontrolltieren auf. In der Magensaftanalyse waren dagegen die Werte der splenektomierten Tiere gegenüber den scheinoperierten nur geringgradig gesteigert. — Als mögliche Ursache der vermehrten Ulcusanfälligkeit nach Splenektomie wurde eine Veränderung lokaler, nicht säuresekretorischer Faktoren der Magenwand diskutiert.
    Notes: Summary In Splenectomiced rats incidence of gastric ulceration was compaired with control groups. Restraint stress and ligation of pylorus was used as model. Splenectomiced rats do show an higher incidence in both models. Both frequency and extension of gastric ulcer were accumulated significantly. Analysis of gastric secretion was only unessentially raised in comparisom to control-groups. Change of protective factors of stomach as possible reason is discussed.
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  • 19
    ISSN: 1432-0738
    Keywords: Alcohol, Ethyl ; Absorption ; Elimination ; Alcohol Oxidoreductases ; Hepatitis, Toxic ; Transaminases ; Glutamate Dehydrogenase ; Guinea Pig ; Rat ; Äthylalkohol ; Resorption ; Elimination ; Alkoholdehydrogenase ; Hepatotoxicität ; Transaminasen ; Glutamatdehydrogenase ; Meerschweinchen ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die maximalen Blutalkoholkonzentrationen nach oraler Gabe von 6,4 g/kg Äthanol in Form einer 40%igen Lösung (v/v) betrugen bei nicht nüchternen Meerschweinchen 6,8±0,3 mg/ml, bei nicht nüchternen Ratten dagegen nur 2,1±0,2 mg/ml. An nüchternen Tieren führte eine orale Alkoholbelastung von 4,8 g/kg zu maximalen Blutalkoholspiegeln von 6,3±0,2 mg/ml bei den Meerschweinchen und 3,7±0,3 mg/ml bei den Ratten. Intravenös injizierter Alkohol (1 g/kg) wurde demgegenüber von beiden Species mit der gleichen Geschwindigkeit eliminiert (275 mg/kg · Std), und die auf das Körpergewicht bezogene ADH-Aktivität der Leber war bei den Meerschweinchen um 20% größer als bei den Ratten. Die Resorption von Äthanol erfolgt somit bei Ratten erheblich langsamer als bei Meerschweinchen. Dies dürfte darauf beruhen, daß konzentrierte Alkohollösungen die Magenentleerung der Ratte stark verzögern. Niedriger konzentrierte Alkohollösungen werden von der Ratte schneller resorbiert; jedoch waren auch nach Gabe von 10%igem Alkohol die maximalen Blutalkoholspiegel bei Ratten noch um 36% niedriger als bei Meerschweinchen. Bei den Meerschweinchen waren nach oraler Gabe von 4,8 bzw. 6,4 g/kg Äthanol die Serumaktivitäten der GOT, GPT und GLDH erhöht; ein Anstieg der SGOT trat schon nach 1,6 g/kg Äthanol auf. Demgegenüber kam es bei Ratten nach 6,4 g pro kg Äthanol p.o. nur zu geringfügigen Aktivitätserhöhungen der Serumtransaminasen, während die Serumaktivität der GLDH unverändert blieb. Vacuolige Degeneration war das morphologische Substrat der durch Äthanol bei Meerschweinchen und Ratten ausgelösten Leberschädigung. Während diese Veränderung bei Meerschweinchen bereits nach einer Äthanoldosis von 1,6 g/kg auftrat, wurde sie bei Ratten erst nach 6,4 g/kg beobachtet. Schlußfolgerung: Das Meerschweinchen ist für Untersuchungen zur Toxicität von Äthanol besser geeignet als die Ratte.
    Notes: Abstract In fed guinea pigs, an oral dose of 6.4 g/kg of ethanol given as a 40% solution (v/v) produced a maximal blood alcohol level of 6.8±0.3 mg/ml, whereas in fed rats, blood alcohol levels after the same dose did not exceed 2.1±0.2 mg/ml. Maximal blood alcohol levels in fasted animals after an oral load of 4.8 g/kg of ethanol were 6.3±0.2 mg/ml in guinea pigs and 3.7±0.3 mg/ml for rats. However, i.v. injected ethanol (1 g/kg) was eliminated at the same rate in both species (275 mg per kg · h), and ADH activity of the liver related to body weight was by 20% greater in guinea pigs than in rats. Therefore, absorption of ethanol occurs at a much slower rate in rats than in guinea pigs. This is possibly due to the fact that high ethanol concentrations strongly delay emptying of the rat stomach. Lowering the ethanol concentration accelerates absorption rate in the rat. However, even after gavage of a 10% solution peak levels of blood alcohol were still lower by 36% in rats than in guinea pigs. In guinea pigs, increased serum activities of GOT, GPT, and GLDH occurred after an oral dose of 4.8 g/kg or 6.4 g/kg of ethanol, respectively. SGOT already increased after 1.6 g/kg of ethanol p.o. After 6.4 g/kg of ethanol given to rats serum transaminase levels increased only slightly, and GLDH activity not at all. Vacuolar degeneration was the morphological substrate of ethanol-induced liver damage in guinea pigs and rats. In guinea-pigs, it occurred already after 1.6 g/kg of ethanol, whereas in rats only after 6.4 g/kg. In conclusion, the guinea pig seems to be better suited for research on alcohol toxicity than the rat.
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  • 20
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    Research in experimental medicine 162 (1974), S. 313-321 
    ISSN: 1433-8580
    Keywords: Coprophagy ; Rat ; Calcium metabolism ; Bone morphology ; Immobilization ; Koprophagie ; Ratte ; Calciumstoffwechsel ; Knochenmorphologie ; Immobilisierung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Wir untersuchten den Einfluß der Koprophagie auf den Calciumstoffwechsel der Ratte. 20 Versuchstiere wurden durch Einschnüren in einen Lederpanzer an der Koprophagie gehindert und mit 21 Kontrolltieren gleicher Futteraufnahme verglichen. Die Kinetik des Calciumstoffwechsels wurde unter Verwendung von45Ca als Tracer analysiert. Die radiochemischen Resultate wurden mit den histologischen Beobachtungen an den Epi-Metaphysen der Kniegelenke verglichen. Bei den Versuchstieren mit verhinderter Koprophagie fanden wir: 1. ein hochsignifikant niedrigeres Körpergewicht; 2. eine hochsignifikante Verkleinerung folgender Parameter des Calciumstoffwechsels: Compartmentgröße und Austauschrate zwischen ihnen, Calciumausscheidungsraten, Knochenan- und -abbau; 3. eine Verschmälerung der Wachstumsfuge, verkürzte und verschmälerte primäre Knochenbälkchen, verminderte sekundäre metaphysäre Spongiosa. Bei 4 Versuchstieren, die in Lederpanzern gehalten, denen jedoch die Koprophagie ermöglicht war, wurden gleichartige histologische Veränderungen wie bei verhinderter Koprophagie festgestellt. Es wird gefolgert, daß die Verhinderung der Koprophagie keinen meßbaren Einfluß auf die Parameter des Calciumstoffwechsels hat.
    Notes: Summary We investigated the influence of coprophagy on the calcium metabolism of the rat. 20 experimental animals were prevented from coprophagy by wrapping them in leather harnesses and compared with 21 controls on the same food intake. Kinetics of calcium metabolism were analysed using45Ca as tracer. The radiochemical results were compared with the histological observations in the epi-metaphyses of the knee joints. In the experimental animals prevented from coprophagy we found: 1. a highly significant lower body weight; 2. a highly significant diminution of the following parameters of calcium metabolism: compartment sizes and exchange rate between them, calcium excretion rates, bone accretion and resorption; 3. a narrower epiphyseal growth cartilage, clearly shorter and narrower primary trabeculae, rarefied secondary metaphyseal trabeculae. Histological alterations identical to those observed with coprophagy prevented, were found in 4 animals kept in harnesses but with coprophagy allowed. It is concluded that prevention of coprophagy has no measurable influence on the parameters of calcium metabolism.
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  • 21
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    Research in experimental medicine 163 (1974), S. 39-45 
    ISSN: 1433-8580
    Keywords: D-penicillamine ; Acetazolamide ; Renal excretion ; Rat ; D-Penicillamin ; Acetazolamid ; Renale Exkretion ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die renale Ausscheidung von D-Penicillamin läßt sich weder durch Probenecid noch durch N-Methylnicotinamid oder NH4Cl beeinflussen. Acetazolamid bewirkt eine erhöhte Retention von D-Penicillamin in Haut und Muskulatur und hemmt dessen renale Ausscheidung, hat jedoch keinen Effekt auf die Dekorporationswirksamkeit von D-Penicillamin bei60Co. Die möglichen Ursachen des Einflusses von Acetazolamid auf die Verteilung und Exkretion von D-Penicillamin werden diskutiert.
    Notes: Summary The renal excretion of D-penicillamine is not influenced by probenecid, N-methylnicotinamide, and NH4Cl. Acetazolamide brings about an increased retention of D-penicillamine in skin and muscles and lowers its urinary excretion, but does not exhibit any influence on the efficacy of D-penicillamine in removing internally deposited60Co. The possible causes for the action of acetazolamide on the distribution and excretion of D-penicillamine are discussed.
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  • 22
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    Research in experimental medicine 163 (1974), S. 289-298 
    ISSN: 1433-8580
    Keywords: Gastrinpentapeptide ; Vagotomy ; Acid secretion ; Perfusion test ; Rat ; Gastrinpentapeptid ; Vagotomie ; Säuresekretion ; Perfusionsversuch ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei männlichen Wistarratten wurde eine trunkuläre beiderseitige Vagotomie — ergänzt durch eine Pyloroplastik — angelegt. 4 Wochen später erfolgte in Urethannarkose eine Perfusion des Magens mit 0,9%iger NaCl-Lösung in Anlehnung an die Versuchsanordnung von Ghosh. Die Vollständigkeit der Vagotomie bestätigte ein Hypoglykämietest. Im Abstand von 150 min erhielten die Tiere — in 6 Gruppen zu je 10 Ratten — 2 × 50, 100, 150, 200, 250 oder 300 µg/kg KG Pentagastrin subcutan. Die statistisch ausgewerteten Ergebnisse lassen sich wie folgt zusammenfassen: 1. Die nach dem Abklingen der Wirkung der ersten Pentagastrininjektion wiederholte Pentagastringabe in derselben Dosis ergab bei allen Dosierungen eine höhere Säuresekretion als nach der ersten Injektion. 2. Ein Maximum der sezernierten Säuremenge wurde bei einer Dosis von 100 µg/kg KG erreicht. Bei höherer Dosierung des Pentagastrins nahm die Menge der sezernierten Säure signifikant ab.
    Notes: Summary Male Wistar rats were subjected to a complete bilateral vagotomy and a pyloroplasty. 4 weeks later followed in urethane anesthesia a continuous perfusion of the stomach with 0.9% saline according to the rat preparation of Ghosh. The completeness of the gastric vagotomy was confirmed by a postoperative insulin test. In an interval of 150 min the rats — in 6 groups of 10 rats each — were two times injected pentagastrin subcutaneously in dose rates of 50, 100, 150, 250 or 300 µg/kg body weight. The statistical confirmed results can be summarized as followed: 1. The second injection of pentagastrin — 150 min after the first — in the same dose produced a significantly higher gastric acid secretion in the rat all dose rates in comparison to the first injection. 2. The maximal gastric acid secretion was produced by a dose rate of 100 µg/kg body weight of pentagastrin. At higher dose rates of pentagastrin there was a significant reduction of gastric acid secretion.
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  • 23
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    Research in experimental medicine 164 (1974), S. 19-33 
    ISSN: 1433-8580
    Keywords: Kidney ; Rat ; Ultrastructure ; Proximal tubule degeneration ; Heparinoid ; Niere ; Ratte ; Ultrastruktur ; Proximale Tubulusdegeneration ; Heparinoid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 24 Std nach i.v. Injektion von 100 mg/kg eines Pentosanschwefelsäureesters (SP 54) sind in der Nierenrinde von Ratten schwere degenerative Veränderungen der proximalen Tubuluszellen zu beobachten. Das Tubulusepithel ist flachkubisch umgewandelt, das Tubuluslumen ist angefüllt mit ausgestoßenen Mitochondrien und anderen Zelltrümmern. Am stärksten betroffen ist die Pars contorta des proximalen Tubulus. Weniger stark veränderte Tubuluszellen sind angefüllt mit Cytosomen, die eine spezifische Feinstruktur haben oder gehäuft gegenüber Kontrollen Cytoplasmaprotrusionen in das Tubuluslumen aufweisen. Die akute Tubulusdegeneration ist ein spezifischer Effekt von SP 54. Heparin bewirkt nur eine leichte Schwellung des Tubulusepithels, die häufiger auftritt als bei Kontrolltieren.
    Notes: Summary 24 hrs after the intravenous injection of 100 mg/kg of a Pentosansulfuricacidester (SP 54) severe degenerative alterations are observed in the proximal tubular cells in rat kidney cortex. The tubular epithelium has changed to a single layer of elongated cubic cells. The tubular lumen is filled with cellular debris and extruded mitochondria. The greatest change is seen in the pars contorta of the proximal tubule. Less degenerated tubular cells have a great number of cytosomes with a specific substructure or have cytoplasmatic protrusions into the tubular lumen. This acute tubular degeneration is a specific event after the administration of SP 54 and is not seen after an equimolar dosis of Heparin. Heparin induces only a slight swelling of the tubular epithelium, more frequent seen as in the control animals.
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  • 24
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    Research in experimental medicine 163 (1974), S. 341-349 
    ISSN: 1433-8580
    Keywords: Experimental uremic syndrome ; Rat ; 5/6 reduction of renal parenchyma ; Serum- and urine analysis ; Secondary hyperparathyroidism ; Experimentelles urämisches Syndrom ; Ratte ; 5/6-Reduktion des Nierenparenchyms ; Serum- und Urinanalyse ; Sekundärer Hyperparathyreoidismus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Durch eine 5/6-Nierenparenchymreduktion wurde an Ratten ein chronisches, durch bilaterale Nephrektomie ein akutes urämisches Syndrom erzeugt. Beim chronischen urämischen Syndrom erwiesen sich in der Serumanalyse die Konzentrationen des Harnstoffstickstoffs und des Kreatinins als wesentlich erhöht. Darüber hinaus bestanden alle chemischen Zeichen eines sekundären Hyperparathyreoidismus. Die Tiere litten außerdem an einer schweren Poly-, Protein- und Albuminurie. Überraschenderweise war aber der Spiegel des totalen Serumproteins gegenüber den Kontrolltieren erhöht. Das experimentelle chronische urämische Syndrom stellt eine extreme Adaptation der regulatorischen Aktivität des Nierenrestparenchyms und des ganzen Organismus dar. Beim akuten, durch bilaterale Nephrektomie erzeugten urämischen Syndrom besteht dagegen ein schweres Versagen der Regulation des Wasser- und Elektrolytstoffwechsels, welches innert 50–60 Std zum Tode der Versuchstiere führt.
    Notes: Summary A chronic uremic syndrome was induced by 5/6 nephrectomy and an acute uremic syndrome by bilateral nephrectomy in rats. In the chronic uremic syndrome serum and urine analysis revealed a highly increased serum level of BUN and creatinine. Furthermore, all chemical signs typical of secondary hyperparathyroidism were present. The animals suffered from severe polyuria, protein- and albuminuria but, surprisingly, the total serum protein was increased. The experimental chronic uremic syndrome is, in essence, a syndrome of “extreme adaptation” of the regulatory activity of remnant renal parenchyma and of the whole body. In contrast, the acute uremic syndrome induced by bilateral nephrectomy is a severe disorder of water and electrolyte metabolism resulting in death of the experimental animals after 50–60 hrs.
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  • 25
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    Pflügers Archiv 352 (1974), S. 121-133 
    ISSN: 1432-2013
    Keywords: Urate ; Protein Interaction ; Uptake by Erythrocytes ; Renal Reabsorption ; Man ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Interaction of urate with human and rat plasma was studied by a dialysis technique at different temperatures. At 4° C a certain fraction of urate is bound to proteins. However, this fraction diminishes with increasing temperature and at 37° C only some 7–8% (in man) and 2% (in rat) interact with proteins. The finding that urate is almost completely filtered in the glomerulus is discussed. In body areas exposed to low temperatures protein binding of urate may be of importance. Urate uptake by erythrocytes is characterized by two components: a fast component equilibrating almost immediately at about 7% in man and 17% in rat and a slow component reaching equilibrium after 60 min, at 28% and 36%, respectively. The process is described by a mathematical formula. Lowering of the temperature mainly diminishes uptake by the slow component withQ 10-values ranging between 1.5 and 4.0. In the observed range of concentrations the uptake process does not saturate. The results at lower pH-values suggest that it is unionized uric acid which is transported by the slow component. Application of the data to kidney medulla supports the hypothesis that erythrocytes and, probably, to a lesser extent plasma proteins serve as vehicles for urate reabsorption in the countercurrent system. Such a temporary interaction enables uric acid to escape recirculation and to leave the kidney medulla.
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  • 26
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    Pflügers Archiv 352 (1974), S. 115-120 
    ISSN: 1432-2013
    Keywords: Urate ; Reabsorption ; Loop of Henle ; Micropuncture ; Microperfusion ; Microinjection ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Reabsorption rates for urate in the loops of Henle were measured in superficial nephrons in the rat 1. under conditions of free flow, 2. using microperfusion and 3. by a microinjection technique. 1. Under conditions of free flow distally measured TF/PUA/TF/PIn-values varied between 0.51 and 0.38 in antidiuretic rats, depending on TF/PIn (UA = both uric acid and urate, In = inulin, TF/P = concentration in tubular fluid to plasma concentration). The corresponding values in samples from end-proximal tubules were 1.06 and in urine 0.19 (U/PUA/U/PIn). 2. In microperfusion experiments of Henle loops early distal recoveries of 2-C14 urate varied between 57 and 86%, depending on the flow rates (10–40 nl/min). 3. In microinjection experiments C14 recovery in urine was about 85% when tracer solution was microinjected into endproximal tubules. From these results we conclude: 1. The main site of urate reabsorption is located in the loops of Henle. 2. This reabsorption is highly dependent on flow rates. Increase of flow rate through Henle's loop decreases urate reabsorption.
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  • 27
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    Calcified tissue international 14 (1974), S. 283-289 
    ISSN: 1432-0827
    Keywords: Sodium fluoride ; Osteoporosis ; Bone ; Strength ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'utilisation thérapeutique de fluorure de sodium a été recommandée dans le traitement de diverses maladies osseuses ostéopéniques. Cet emploi est basé principalement sur les effects ostéosclérotiques bien connus du fluorure de sodium, mais on connait mal son effet sur la force de résistance osseuse. L'influence de diverses concentrations de fluorure de sodium sur la force de résistance osseuse de jeunes rats soumis à des régimes riches et pauvres en calcium a été étudiée. L'administration de fluorure de sodium augmente le diamètre osseux, indiquant une stimulation de la formation de l'os périosté, mais la force de résistance osseuse est réduite ou non modifiée par l'ingestion de fluor.
    Abstract: Zusammenfassung Die therapeutische Verwendung von Natriumfluorid ist für eine Anzahl von Knochenmangel-Krankheiten empfohlen worden. Die Empfehlungen basieren hauptsächlich auf den bekannten osteosklerotischen Wirkungen von Natriumfluorid; über dessen Effekt auf die Knochenstärke ist wenig bekannt. In dieser Arbeit wurde der Einfluß verschiedener Konzentrationen von Natriumfluorid auf die Knochenstärken von wachsenden Ratten mit hoher und niederer Calciumeinnahme untersucht. Die Verabreichung von Natriumfluorid erhöhte den Knochendurchmesser, was auf eine Stimulierung der Periostbildung hinwies, die Knochenstärke wurde jedoch durch Fluorideinnahme herabgesetzt oder nicht beeinflußt.
    Notes: Abstract The therapeutic use of sodium fluoride has been recommended in a variety of osteopenic bone diseases. The recommendations are based mainly on the known osteosclerotic effects of sodium fluoride and little information is available as to its effect on bone strength. The influence of various concentrations of sodium fluoride on bone strength in growing rats on high and low calcium diets was studied. The administration of sodium fluoride increased bone diameter, indicating stimulation of periosteal bone formation, but bone strength was reduced or not affected by fluoride ingestion.
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  • 28
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    Naunyn-Schmiedeberg's archives of pharmacology 281 (1974), S. 197-217 
    ISSN: 1432-1912
    Keywords: Intestinal Absorption ; Acidic Drugs ; Benzoic Acid ; Salicylic Acid ; Solvent Drag ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Jejunal loops of anaesthetized rats were perfused with hypotonic, isotonic and hypertonic buffered solutions containing 14C-labelled benzoic acid and salicylic acid at pH 6.2 and 2.2. The blood flow of the loop was maintained at an intermediate rate (0.78–0.97 ml min−1 g−1). The water net flux was determined by polyethylene glycol as non-absorbable marker and amounted up to +31 or-27 μl min−1 g−1. 2. A positive water net flux (leaving the gut lumen) increased the appearance rate of benzoic acid and salicylic acid in the intestinal venous blood by maximally 47 and 41%, a negative water net flux (entering the gut lumen) diminished the appearance rate by 28 and 37%. 3. The experimental data were analysed by means of a kinetic model. The parameters of the model were the epithelial permeability kF D , the serosal permeability k S F S and the sieving coefficient Φ=1−σ. The epithelial permeability was 0.115 and 0.107 for benzoic acid and salicylic acid at pH 6.2 and increased to 0.163 and 0.185 ml min−1 g−1 at pH 2.2. The serosal permeability was assumed to be identical for neutral and acidic pH and amounted to 0.046 and 0.112 ml min−1 g−1 indicating that a certain proportion of the absorbed drugs was transferred to the serosal side. The sieving coefficient was 2.92 and 2.31 at neutral pH and 3.79 and 3.56 at acidic pH. 4. The main resistance to the absorption of the two drugs is the epithelial membrane, since the effective blood flow and the unstirred layer are not ratelimiting. The high sieving coefficient for the two drugs is interpreted as indicating an interaction of drug and water molecules inside the lipid part of the cell membrane (which contains at least 30% water). The electric potential across the gut wall may contribute to the size of the sieving coefficient, if the drug molecules permeate also in the ionized form. 5. Using acidic perfusion solutions the epithelial permeability and the sieving coefficient were increased by the factor 1.3–1.5. This increase can be explained sufficiently by a facilitated entrance of the unionized drug molecules into the epithelial membrane.
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  • 29
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    Naunyn-Schmiedeberg's archives of pharmacology 285 (1974), S. 175-184 
    ISSN: 1432-1912
    Keywords: Fenfluramine ; Rat ; Guinea Pig ; Phospholipidosis, drug-induced ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After administration of the anorectic drug fenfluramine (40 mg/kg per day) to rats (s. c. or i. p.) and guinea pigs (p.o.) over periods of 2 to 11 weeks, electron microscopic examination was performed on lungs, liver, lymphatic tissues and peripheral blood of both species, and on adrenal glands and ovaries of rats. In rats, fenfluramine caused the following alterations (listed according to the duration of treatment): Formation of abnormal lamellated inclusions in lymphocytes and plasma cells of lymphatic tissues, appearance of “foam cells” in lung alveoli; formation of abnormal lamellated inclusions in corpus luteum, lymphocytes of peripheral blood, and in adrenal cortex. In guinea pigs, the same alterations were found in lymphocytes of spleen and peripheral blood, in hepatocytes and in lung. The present observations support the concept of a generalized phospholipidosis induced by amphiphilic compounds. The potency of fenfluramine to induce a lipidosis is, however, considerably less pronounced than that previously demonstrated for the anorectic drug chlorphentermine. This difference is suggested to be due mainly to the lower degree of amphiphilia of fenfluramine.
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  • 30
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    Naunyn-Schmiedeberg's archives of pharmacology 282 (1974), S. 195-212 
    ISSN: 1432-1912
    Keywords: Intestinal Blood Flow ; Intestinal Absorption ; d-Galactose ; Phlorizine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Jejunal loops of anaesthetized rats were perfused with buffered solutions (pH 6.8) containing d-galactose in two concentrations: below (100 μM) and above (100 mM) blood sugar concentration. The blood flow rate, the appearance rate (in the intestinal venous blood) and the disappearance rate (from the intestinal lumen) were determined simultaneously, the accumulation in gut tissue at the end of the experiments. 2. At constant intermediate blood flow the appearance rate and disappearance rate decreased with time. A decrease of the blood flow rate from about 1.9 to about 0.3 ml min−1 g−1 diminished both the appearance and the disappearance rate. An increase of blood flow from about 0.3 to about 1.9 ml min−1 g−1 did not increase the absorption rates; even a slight decrease was observed. 3. In the presence of phlorizine (2 mM) the absorption rates and the tissue accumulation of galactose is reduced. At constant intermediate blood flow the appearance and disappearance rate increased with time. A decrease of the blood flow rate from about 1.8 to about 0.3 ml min−1 g−1 diminished the appearance rate. An increase of the blood flow rate from about 0.3 to about 1.8 ml min−1 g−1 caused an increase of the appearance rate in contrast to the experiments without phlorizine. Therefore, the different blood flow dependence of the intestinal absorption observed with actively transported substances can be attributed to their non-passive component.
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  • 31
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    Naunyn-Schmiedeberg's archives of pharmacology 281 (1974), S. 175-196 
    ISSN: 1432-1912
    Keywords: Intestinal Absorption ; Basic Drugs ; Amidopyrine ; Antipyrine ; Solvent Drag ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Jejunal loops of anaesthetized rats were perfused with hypotonic, isotonic and hypertonic buffered solutions containing 14C-labelled amidopyrine and antipyrine at neutral and at acidic pH. The blood flow of the loop was maintained at an intermediate rate (0.7–1.0 ml min−1g−1). The water net flux was determined by means of polyethylene glycol as non-absorbable marker and amounted up to ±30 μl min−1g−1. 2. A positive water net flux (directed towards the blood) increased the appearance rate of amidopyrine and antipyrine by maximally 43.8 and 49.2%, a negative water net flux (directed towards the gut lumen) diminished it by 38.8 and 35.0%. 3. The experimental data were analysed by means of a kinetic model with the water net flux as independent variable and the epithelial permeability kF D , the serosal permeability k S F S and the sieving coefficient Φ=1−σ as absorption parameters. For antipyrine independent of the pH-value of the perfusion solution kF D was 0.123, and, for amidopyrine at pH 7 and pH 3 kF D was 0.231 and 0.091, respectively. k S F S was zero indicating that in this experimental arrangement the transfer of drug molecules to the serosal side was negligible. The sieving coefficient Φ amounted to 2.30 for amidopyrine and 2.15 for antipyrine at neutral pH. At acidic pH it amounted to 0.50 for amidopyrine and 1.44 for antipyrine. The hydraulic permeability of water was identical at neutral and acidic pH. 4. The high sieving coefficient for the two drugs at neutral pH is interpreted as indicating that water and lipophilic drug molecules interact within the lipid part of the cell membrane. At acidic pH the ionized drug molecules appear to permeate the cell membrane preferentially across other (presumably more hydrophilic) areas.
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  • 32
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    Pflügers Archiv 350 (1974), S. 241-248 
    ISSN: 1432-2013
    Keywords: Cardiac Hypertrophy ; Diffusion Distance of Oxygen ; High Altitude ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rats born and staying their whole life at a simulated altitude of 3500 m a severe cardiac hypertrophy develops which is most pronounced in the right ventricle. On histological sections muscle fiber and capillary densities were counted and the surfaces occupied by muscle fibers and capillaries in the slides were estimated. Mean muscle fiber diameter and half mean distance between capillaries (diffusion distance) were obtained in the heart ventricles and were compared with those of control animals. In both ventricles an increase of the mean muscle fiber diameter occurred (true hypertrophy), being more pronounced in the right ventricle. We cannot tell whether also hyperplasia of muscle fibers occurred or not. The diffusion distance in the left ventricle of rats exposed to hypoxia was about the same as in control animals but was shorter in the right ventricle. This indicates that the total number of capillaries is higher in both ventricles of rats born in the low pressure chamber (hyperplasia of the capillaries). The shortening of the diffusion distance in the right ventricle of rats born and living their whole life at simulated high altitude was on the average smaller than that of rats exposed to simulated high altitude later in life. The physiological importance of this observation is discussed.
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  • 33
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    Pflügers Archiv 351 (1974), S. 13-24 
    ISSN: 1432-2013
    Keywords: Hypothalamus ; Spike-Trains ; Correlogram/Periodogram ; Thermosensitivity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stationary spike-trains of preoptic neurons of the rat were submitted to a correlation- and spectral-analysis at normal temperature and after central warming and cooling. Correlograms and periodograms were computed which enable the elimination of stochastic signal components and the identification of the relevant periodic components. About one half of the analysed neurons showed periodic correlograms. The following three classes may be distinguished: Neurons which showed correlograms with periodicities at each applied thermal state, at only one or two thermal states and those with no recognizable periodicities at all. Relations between periodicity and the thermosensitivity of the neurons are discussed.
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  • 34
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    Pflügers Archiv 351 (1974), S. 323-330 
    ISSN: 1432-2013
    Keywords: Uricase ; Urate ; Allantoin ; Liver ; Kidney ; Microperfusion ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. In vivo uricase activity was tested in rats by injection of 2-C14 urate and measurement of the total C14 activity and the fractional activities of allantoin, allantoic acid and urea in samples of blood and urine. In control animals, 5 min after the injection, 70% of the plasma tracer was already present in the form of allantoin. No allantoic acid and urea were produced. Intestinectomy had no measurable influence on uricase activity. On the other hand, hepatectomy or ligation of the hepatic artery combined with subtotal viscerectomy did abolish uricase activity almost completely. 2. Following microinjections into proximal tubules of Ringer solution containing 2-C14 urate, urine samples during early recovery mainly contained labelled urate, whereas in later samples the fraction of labelled allantoin increased. About 12 min after the microinjection the urine of both kidneys contained equal amounts of tracer mainly in the form of allantoin. 3. When segments of proximal tubules were perfused with an equilibrium solution containing tracer amounts of C 14 urate, no urate was metabolized during its passage through the proximal tubule. 4. C 14 urate was offered from the peritubular capillaries and samples of tubular fluid were analyzed, Again, all the tracer in the tubular fluid was in the form of urate, indicating that urate is not oxidized when it is transported across the tubular cell. It is concluded from these results that: 1. The rat kidney has no significant uricase activity. 2. Urate transport in the kidney is not influenced by this enzyme. 3. The degradation of urate to allantoin takes place at extrarenal sites, mainly in the liver.
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  • 35
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    Psychopharmacology 37 (1974), S. 91-100 
    ISSN: 1432-2072
    Keywords: Ethanol ; Brain Serotonin Turnover ; Tolerance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In rats treated acutely and chronically with ethanol, brain serotonin (5-HT) turnover was determined by measuring in the same animals the rate of accumulation of 5-HT and the rate of decline of 5-hydroxyindoleacetic acid (5-HIAA) in the brain after administration of the MAO inhibitor pargyline-HCl. In the acute study, 5-HT turnover was not altered after a single 4 g/kg oral dose of ethanol. In two separate studies, it was shown that chronic administration of ethanol in the form of a liquid diet for 32 days also did not alter brain 5-HT turnover, even when the rats had developed a significant degree of tolerance to the motor-impairing effects of ethanol. These results suggest that tolerance to ethanol is unrelated to any change in brain 5-HT turnover.
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  • 36
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    Psychopharmacology 37 (1974), S. 249-254 
    ISSN: 1432-2072
    Keywords: Chlorpromazine ; Rat ; Social Interaction ; Exploration ; General Motor Activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract When two animals were placed in a hole-board the number of headdips made by each rat was twice the number made when tested alone, but was the same for pairs of drugged (2 mg/kg chlorpromazine) and undrugged rats, and for pairs where only one rat was drugged. This contrasts with the reduction of headdipping produced by chlorpromazine in single animals. However, chlorpromazine still reduced general motor activity, regardless of whether the partner was drugged or not. The activity of the undrugged rats was affected by the partner's state and was lower when the partner was drugged.
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  • 37
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    Psychopharmacology 39 (1974), S. 237-244 
    ISSN: 1432-2072
    Keywords: Antagonism ; Fixed Interval ; Scopolamine ; Physostigmine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of this research was to determine if 2 drugs, scopolamine and physostigmine which have opposite effects on cholinergic transmission also produce opposite effects on fixed-interval (FI) performance. Scopolamine and a wide range of doses of physostigmine were administered singly and concurrently to a number of rats responding on a FI 2 min schedule. Scopolamine produced a disruption in FI curvature which could be antagonized by physostigmine, but physostigmine by itself produced no consistent change.
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  • 38
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    Psychopharmacology 35 (1974), S. 341-352 
    ISSN: 1432-2072
    Keywords: 6-Hydroxydopa ; Rat ; Behaviour ; Biogenic Amines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The influence of 6-hydroxydopa (6-HDP) injected into the lateral ventricles of rat brain on the behaviour of animals was examined. The level of noradrenaline (NA), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in discrete areas of the brain was also measured. 6-HDP was injected in a dose of 100 or 150 Μg into both lateral ventricles, or in a dose of 200 Μg into the right lateral ventricle. Immediately after 6-HDP injection, circling movements, convulsions, aggressive behaviour, and Stereotypic activity were seen. These components of behaviour were most obvious during the first hour after injection of 6-HDP. During one month after 6-HDP administration the behaviour of rats did not differ significantly from the behaviour of control animals, only very subtle differences in behaviour being seen. The dose of 150 Μg of 6-HDP caused aphagia and loss of body weigth during the first 5 days after treatment. 6-HDP also caused hypothermia. 20 min after administration of 200 Μg of 6-HDP a decrease of the NA level but no changes in the 5-HT level in the brain cortex were seen. The same changes were observed 1 month after 6-HDP treatment. The dose of 150 Μg of 6-HDP decreased the NA level in the brain cortex, cerebellum, mesencephalon and brain stem 5 days after treatment. 5-HT content was not changed and the 5-HIAA level was increased in the same brain areas. The dose of 100 Μg of 6-HDP, 2 weeks after the treatment decreased the content of NA in the brain cortex, cerebellum, hypothalamus and brain stem without changes in 5-HT content. 5-HIAA level was elevated only in the brain stem. It is concluded that 6-HDP is a long-acting potent depletor of NA in rat brain. There is a different sensitivity of brain areas to the depleting effect of 6-HDP. 6-HDP does not deplete the 5-HT content of discrete areas of brain but increases the level of 5-HIAA. 6-HDP causes distinct behavioural changes shortly after the treatment. It does not change the behaviour of rats between 1 and 30 days after its administration.
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  • 39
    ISSN: 1432-2072
    Keywords: LSD-25 ; UML ; 5-HT ; Brain ; Platelets ; Behaviour ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Factorial analysis of rat cerebral 5-HT values observed following intraperitoneal LSD-25 and UML (1-methyl-d-lysergic acid butanolamide) showed that the highly significant decrease induced by both drugs was independent of dose and that the effect of both drugs was the same. Increased platelet 5-HT values were also obtained with each drug. These findings suggest that the psychotomimetic effect of LSD-25 is not due to changes in cerebral 5-HT, since a relationship can probably be postulated between such an effect in man and the effect of LSD-25 on conditioned behaviour in the rat. It is also felt that the fact that these drugs decrease and increase cerebral and platelet values respectively may be of assistance in the interpretation of data relating to platelet 5-HT patterns in man under psychiatric conditions and during treatment with psychotropic drugs.
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  • 40
    ISSN: 1432-2072
    Keywords: Rat ; Chlordiazepoxide ; Diazepam ; Extinction ; Avoidance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a one-way avoidance task with rats, injections of Librium (chlordiazepoxide) following avoidance acquisition resulted in prolonged resistance-to-extinction of the avoidance response. This effect occurred regardless of whether the rats had had prior experience with Librium or whether they were naive with respect to the drug. The same results were found with the same task when low doses of Valium were used. However, at a higher dosage an “extreme reaction” of either no responding or a high number of responses to extinction occurred in the naive animals. The Librium and Valium effects were compared to similar effects obtained using ethanol and hashish resin. These results indicate that the novelty hypothesis as originally stated by Amit and Baum cannot be supported because experience with the drugs prior to avoidance training did not attenuate the drug effect on avoidance.
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  • 41
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    Psychopharmacology 40 (1974), S. 91-99 
    ISSN: 1432-2072
    Keywords: Lithium ; Social Behaviour ; Sex ; Novelty ; Photographs ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of lithium chloride on the social behaviour of male and female rats were measured in unfamiliar and familiar test situations using a photographic technique. Lithium-treated females showed an increase in body contact and a decrease in social distances in comparison with saline-treated controls in both test conditions. Males administered lithium showed increased corner occupancies in the novel test setting while in the familiar test they showed decreased body contact and increased average group social distance in comparison with the saline condition. Further tests in an exploration box confirmed that lithium decreased the general environmental responsiveness of male rats. The results are discussed with reference to the anti-aggressive effect of lithium.
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  • 42
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    Psychopharmacology 36 (1974), S. 323-335 
    ISSN: 1432-2072
    Keywords: Methamphetamine ; Rat ; Conditioned ; Aversion ; Space ; Saccharin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Three experiments were performed on Sprague-Dawley derived rats in which 3.0 mg/kg, i.p., injections of methamphetamine were paired with either, (1) a distinctive spatial enclosure, i.e., either a black or gray portion of a shuttle box with discriminably different flooring, (2) the enclosure plus 0.1% saccharin solution availability in the home cage, or (3) the enclosure plus 0.1% saccharin solution availability in that area. Following three drug pairings which alternated with saline injections paired with a different enclosure or enclosure plus H2O availability, a choice of either spatial (1), or spatial plus gustatory stimuli (2,3) which included the original CS's, were presented under non-drug, non-injection conditions. Control groups received saline injections each day under identical conditions. No aversion to the enclosed area, which had been paired with the drug was demonstrated under (1), gustatory (P=0.005) but not spatial aversion was in evidence in the second paradigm, and spatial (P=0.01) and gustatory (P〈0.01) aversion was exhibited in the last study. It was concluded that subsequent aversion to distinctive spatial enclosures following methamphetamine injections was not as strong an effect as similar aversions to gustatory stimuli. Furthermore, the effect only obtained to neutral and not to preferred spatial areas at the dose level tested and in the apparatus used in those studies.
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  • 43
    ISSN: 1432-2072
    Keywords: Rat ; Successive Discrimination ; Conditioned Avoidance Response ; Nerve Impulses ; α-Methyltyrosine ; Tetrabenazine ; l-Dopa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of the administration of l-Dopa, 10 or 100 mg/kg i.p., on the α-methyltyrosine methylester HCl (α-MT; 250+50 mg/kg i. p.) or tetrabenazine (TBZ; 2 mg/kg i.p.)-induced suppression of a successive discrimination-conditioned avoidance task has been studied. It was found that administration of the high l-Dopa dose resulted in a reversal of the α-MT- or TBZ-induced suppression of the avoidance behaviour, although the discrimination was lost. Restoration of the avoidance behaviour and the correct discrimination was obtained with the low l-Dopa dose after α-MT but not after TBZ. The difference in the behavioural response to l-Dopa after α-MT as compared to the response obtained after TBZ is discussed in terms of the availability of the catecholamines formed from l-Dopa for release by the nerve impulses. Biochemical determinations of brain noradrenaline and dopamine were made in parallel. Further, a simple and reliable method for the aquisition of a successive discrimination in the rat is described.
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  • 44
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    Psychopharmacology 39 (1974), S. 309-314 
    ISSN: 1432-2072
    Keywords: Avoidance ; Drug ; Psychotropic ; Rat ; Sidman Schedule ; Sulpiride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Sulpiride, a new psychotropic drug with neuroleptic activity, was administered to rats in a Sidman avoidance schedule. Doses ranging from 1 to 80 mg/kg resulted in the animal receiving fewer shocks. This effect was not correlated with an increase of responding and seemed unrelated to the suppressing action abruptly observed at high doses (i. e. 150 to 200 mg/kg). These results differ from those classicaly obtained with other neuroleptics.
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  • 45
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    Research in experimental medicine 162 (1974), S. 63-66 
    ISSN: 1433-8580
    Keywords: Rhyolithic pumice ; Ferrihexacyanoferrate (II) ; Thallium ; Rat ; Rhyolithischer Bims ; Ferrihexacyanoferrat (II) ; Thallium ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Orale Verabfolgung von rhyolithischem Bims bewirkt eine herabgesetzte Retention von Thallium in den Geweben. Die Wirksamkeit von Rhyolith zeigt eine ausgeprägte Dosisabhängigkeit, ist aber geringer als die von Ferrihexacyanoferrat (II).
    Notes: Summary Oral administration of rhyolith leads to a diminished retention of thallium by the tissues. The effectiveness of rhyolith markedly depends on its dosage, but is surpassed by that of ferrihexacyanoferrate (II).
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 178 (1974), S. 631-635 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The patterns of the superficial veins of the cubital region were studied in 536 Indian subjects both living and dead. Three basic pattern types were noted. Type I had a median cubital vein joining the cephalic and basilic veins in the cubital region. Type II had the cephalic vein itself draining into the basilic vein in the cubital region. Type III showed the absence of a direct communication between the cephalic and basilic veins in the cubital region. The median vein of the forearm in these latter cases joined either of the cephalic and the basilic veins (type III A) or after bifurcating into a median cephalic and a median basilic vein joined both these veins (type III B). Type I was found to be the most common pattern (67.5%) followed by type II (19.5%), with types III A and III B accounting for 6% and 6.5% of the cases, respectively. Renaming of the median cubital vein as the oblique cubital vein because of its direction and renaming of the median basilic and lateral basilic veins as medial and lateral cubital veins since they follow the medial and lateral borders of cubital fossa respectively has been suggested.
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    The @Anatomical Record 178 (1974), S. 657-665 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The ultrastructure of ependymal cells of the median eminence in young Pacific blacktip reef sharks is described. Three major cell types have been observed. The first type is an irregularly-shaped, electron dense cell with many long microvilli and occasional cilia projecting into the ventricle. A second type contains dense cytoplasmic granules in sizes ranging from 1000-2000 Å, and may be morphologically equivalent to “liquor-contacting neurons” observed in ependymal linings elsewhere. The third type appears very similar to crown cells of saccus vasculosus of this and other species. Cells of the third type possess large, lipid-like inclusions, bulbous projections originating from basal bodies, and prominent smooth endoplasmic reticulum. The crown-like cells are compared to cells of saccus vasculosus of young and adult sharks, and their possible significance is discussed.
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    The @Anatomical Record 178 (1974) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 49
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
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    Notes: Following treatment with propylthiouracil, most chondrocytes in the reserve and upper proliferation zones in the tibial epiphyseal plate exhibit degenerate ultrastructural morphology. In the extracellular matrix, sulfated mucopolysaccharide is reduced, matrix vesicles are increased both in number and in size, apatite crystals are present in all zones, and mineralization is enhanced.In post-treatment recovery, chondrocyte degeneration decreases; however, the extracellular matrix is considerably delayed in returning to conditions comparable to those in corresponding controls and this is indicated by the continued presence of apatite crystals in abnormal locations.Chondrocyte degeneration, sulfated mucopolysaccharide, and matrix vesicles, are discussed as they relate to the mineralization process.
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  • 50
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The postnatal growth of the lung was quantitatively investigated in rats aged 1, 4, 7, 10, 13, 21, 44 and 131 days by light and electron microscopic morphometry.Lung volume (VL) increased first directly with body weight (W). After day 10 VL followed the function W0.70. Based on the quantitative findings the postnatal lung growth could be divided into three phases.1Lung expansion (up to day 4): Lung volume increase resulted almost exclusively from an 87% enlargement of the existing air spaces.2Tissue proliferation (day 4 to 13): All tissue compartments showed a pronounced mass increase, followed by a high gain in capillary volume. Alveolar and capillary surface areas (Sa, Sc) developed rapidly due to subdivision of the primitive air sacs.3Equilibrated growth (third week to adult age): An initial period of redistribution of tissue mass with septal lengthening and further rapid increase in Sa and Sc was followed by proportionate alveolar growth. In the adult further lengthening of the interalveolar septa or continued alveolar formation could not be excluded.During the period of fundamental internal remodelling of the lung, its function, as determined by the morphometric pulmonary diffusing capacity, was not impaired.
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Whole-body autoradiograms were prepared from intact and hypophysectomized (Hypox) rats after receiving 125I-HGH iv. In addition, some hypox rats received unlabeled HGH or ACTH six minutes before receiving the 125I-HGH. Hypox rats had greater concentrations of radioactive material in the renal cortex, adrenal cortex, liver and submandibular gland than was present in blood. Pretreatment with ACTH increased the radioactive material in the inner zones of the adrenal cortex; liver and renal cortex contained more radioactive material than blood; and the submandibular gland contained an amount equal to that in blood. Pretreatment with unlabeled HGH greatly suppressed uptake of radioactivity in liver and adrenal cortex and slightly increased the uptake in the renal cortex. Radioactivity could not be detected in the renal medulla or urine of any of the rats. No concentration of radioactive material greater than that seen in blood was present in any other organ or tissue in any of the groups. In the intact rats, the kidney and the adrenal cortex had the greatest concentrations of radioactivity, while the concentration in the liver was equal to that in blood. Autoradiograms were also prepared from sections from untreated hypox rats that were dipped in 125I-HGH solutions. These confirmed the presence of binding sites in the adrenal cortex and liver for 125I-HGH. No binding of radioactive material was seen in the kidney.
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  • 52
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The ultrastructure of articular cartilage of the femoral head was examined in growing male mice of strain C57Bl fed diets containing supplements of 25 or 40% corn oil for periods of 10 days, 2 and 4 weeks and 2 and 3 months. The ration containing 25% corn oil did not produce conspicuous effects. The ration containing 40% corn oil exerted a slight stimulation on the size, the ER, and the mitochondria of the articular chondrocytes. The findings are consistent with the long range effects of oil-enriched diets on the knee joints of mice and in particular with the failure of such diets to promote the development of osteoarthrosis in mice of strain C57Bl. The results are discussed in relation to earlier observations of the injurious action of diets containing comparable amounts of saturated fat.
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  • 53
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Each of the major coronary arteries of 25 fresh sheep hearts was injected with a different colored barium gelatin mass. Histologic sections were made of the AV node and His bundle in nine hearts. The blood supply to this region was traced radiographically, photographically and histologically. X-rays of the upper ventricular septum were taken before and after coronary injection to demonstrate an os cordis.The sinus node is always supplied by a branch of the right coronary artery. The crux of the heart, and subsequently the AV node, is always supplied by the circumflex artery. The unbranched His bundle, unusually long in sheep, receives a dual blood supply from both the anterior septal branches and the AV node artery. The proximal part of the left and right bundle branches is supplied by the anterior septal branches in the majority of hearts. Intercoronary anastomoses are present in the majority of hearts, particularly in the upper ventricular septum.An os cordis, deep in the atrial septum and directly adjacent to the AV node, was found in all 25 hearts. Occasionally, a second bone was found in the anterior part of the left atrioventricular ring.
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  • 54
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    The @Anatomical Record 179 (1974), S. 241-251 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The postnatal development of the ovary in the bank vole and vole was investigated in order to determine whether the earlier onset of puberty in the vole coincides with a difference in the speed of gonadal development during the immature period in the two species.The ovarian development differed in three respects: in the vole 4-10% of the germ cells are still oogonia when the animal is born, while in the bank vole oocytogenesis is completed during the embryonic period. Follicles develop earlier and more rapidly in the vole than in the bank vole. The early appearance of fluid accumulation in the follicles and the formation of “fluid sacs” in the vole ovary is characteristic.
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  • 55
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    The @Anatomical Record 179 (1974), S. 273-284 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Extensive subsurface cisterns were commonly found beneath the apposed plasmalemmas of adjoining hepatocytes in young and adult mice. The cisterns were of two types: (1) flat cisterns, often with ribosomes on their deep surface, and (2) flattened, highly fenestrated smooth surfaced saccules, some of which were in continuity with smooth endoplasmic reticulum. Despite their frequent occurrence, the subsurface cisterns were always absent from the regions of gap or tight junctions, as well as from the periphery of bile canaliculi and cell surfaces bordering the space of Disse. The function of these cisterns remains undetermined.
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  • 56
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    The @Anatomical Record 179 (1974), S. 285-296 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The fine structural appearance of eight spontaneously polyspermic rabbit zygotes was studied. The zygotes were considered polyspermic only after they met all criteria that excluded other possibilities of the trinucleate state. The presence of accessory male pronuclei, with varying degrees of disintegration of their chromatin in zygotes of similar age, suggests that refertilization can occur during an interval of several hours after penetration of the primary sperm. All of the polyspermic zygotes contained cortical granules intermittently beneath the vitelline (plasma) membrane. One zygote possessed cortical granule-like structures with ill-defined or no limiting membrane. Formation of enveloping membranes around the incorporated accessory sperm head was precocious since it occurred prior to disintegration of the chromatin. Advanced stages of accessory pronuclei morphologically resembled the primary pronuclei in the same zygote. In seven out of eight zygotes the accessory male pronucleus was separated from the apposing male and female pronuclei. It was concluded that although the fully expanded accessory male pronucleus is similar to the pronuclei of monospermic fertilization, the temporal events of nuclear envelope formation were disturbed.
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  • 57
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    The @Anatomical Record 179 (1974), S. 331-341 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The numbers and diameters of nerve fibers were determined for the first time for all interganglionic rami of the sympathetic chain of the frog. The number of myelinated fibers ranged from 57 to 263 and was generally highest in the anterior portion (207) and lowest at the posterior end (57) of the chain. The exception was between the fourth and fifth ganglia where the middle splanchnic nerves arise  -  the number of myelinated fibers was highest here (263). Unmyelinated fiber counts were similar throughout the chain (417-814) except above and below the first sympathetic ganglion (7325 and 3026, respectively), and at the level where the middle splanchnic nerves arise (3780). Unmyelinated fibers constituted 75-97% of the fibers of the chain. The myelinated fibers ranged in diameter from 0.5 to 9.0 μ, 75% of them measuring between 1.5 and 3.0 μ. The diameter range for unmyelinated fibers was 0.1 to 5.0 μ with 78% being 0.1 to 1.0 μ.
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  • 58
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    The @Anatomical Record 179 (1974), S. 343-359 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The processes of myogenesis and elastogenesis are studied under the electron microscope in developing rat lungs, throughout the 15th to the 21st days of the gestation period. Myogenesis follows bronchial development and stops at the beginning of the alveolar zone, at the primitive respiratory bronchiole level. Elastogenesis appears at the periphery of the myoblasts during their differentiation. Thin myofilaments only are observed within myoblasts and their formation precedes that of dense bodies.Primitive respiratory bronchioles are visible on the 19th day and are characterized by an early elastogenesis carried out by fibroblasts. At this stage there are no elastic fibers around the alveolar tubules. Then (20th and 21st days) elastogenesis spreads throughout the alveolar zone, accompanying the alveolization process. Peculiar morphological characteristics of the pulmonary fibroblast are underlined. In relation to both muscular cells and fibroblasts the fine structural features of the rat pulmonary elastogenesis are identical to those previously described in other organs. Myoblasts and fibroblasts probably originate from the same primitive mesenchymal cell. Their differentiation depends on the zone where they are located. The relations between connective tissue and epithelial cell differentiation suggest a control of lung development by means of reciprocal induction processes.
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  • 59
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    The @Anatomical Record 179 (1974), S. 447-451 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The number and spatial relations of muscle spindles in the extensor indicis have been determined. Approximately forty spindles lie adjacent to the motor end plate zone dispersed rather equally through this area of the muscle with a modest increase in density among the distally originating fibers. A study of the entire innervation pattern of this muscle has also been completed.These findings have greatly facilitated the isolation of spindles for electron microscopic study and attempts to perform in vivo recording from the sensory nerves of muscle spindles in this laboratory. It is now possible, with the aid of suitable magnification and stimulating and recording devices, to more rapidly find muscle spindles relative to the gross innervation and the easily located motor end plate zone.
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  • 60
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Human muscle spindles are isolated from muscle biopsies of Extensor Indicis. A spindle rich portion of muscle is removed, placed into a modified Kreb's solution and microdissected for spindles. Intramuscular nerves and blood vessels provide helpful locating guides. Spindles can be dissected free of extrafusal muscle with an adequate length of nerve for in vitro recording. Another portion of muscle is stretched and placed into a 5% glutaraldehyde fixative in 0.1 M cacodylate buffer. Spindles are dissected free, postfixed, dehydrated, stained, and then studied with the light microscope while in liquid Epon. The equatorial regions are identified, then removed and embedded for examination using the electron microscope. This is the first successful total isolation of viable human spindles. The combined procedures allow correlation of recordings from the primary sensory endings with the fine structure of spindles from normal persons and from patients with neuromuscular disorders.
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  • 61
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    The @Anatomical Record 179 (1974), S. 477-480 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The functions of the normal semispinalis capitis and splenius capitis muscles of fifteen subjects were evaluated electromyographically with bipolar fine-wire electrodes. The voltage-output data were integrated and analyzed by computer and showed that the main function of semispinalis capitis is limited to extension of the head. However, splenius capitis both extends the head and rotates it to its own side.
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  • 62
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    The @Anatomical Record 179 (1974), S. 491-496 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Electron microscopy of the turtle sinus venosus shows an unusual neuron soma which is immediately surrounded by myocardial cells so as to form a somato-muscular complex. Studies of 36 sections cut through this neuron soma indicate that 27.4% of the somal surface studied is directly covered by cardiac muscle cells without any intervening basal lamina. Similarly, 18.8% of the somal surface studied is in contact with unmyelinated axons which at places make typical axosomatic synapses. A coupling of peripheral cisterns of the sarcoplasmic reticulum and the sarcolemma exists at the somato-muscular contiguity as well as at the border between cardiac muscle cells. It is suggested that neural influences upon the pacemaking activity of the turtle heart sinus can well be exerted through the somato-muscular pathway. Additionally, an axon which is presynaptic to the neuron soma has been observed to be simultaneously in a synaptic relation with a cardiac muscle cell; a remarkable deviation from the classical picture of the efferent nervous outflow to the heart.
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  • 63
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    The @Anatomical Record 178 (1974) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 64
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Keratinization or mucification of the epithelium of the rat vagina is related to the hormonal state of the animal. During the normal cycle and after the administration of exogenous hormones (estrogen and progestin) to spayed animals, the surface characteristics and topography of the vaginal epithelium were studied with the scanning electron microscope. During estrus and under the influence of estrogen, the superficial cells were keratinized, overlap each other like shingles, and are continuously sloughed off. Like the surface of other keratinizing epithelia, theirs has a characteristic microridge pattern. In ovariectomized animals, the apical surface is covered with microvilli instead of microridges, and the cells resemble hexagonally shaped units, tightly bound instead of overlapping each other. At the boundary between the cells, a ridge demarcates the cells. The surface configurations of progestin-treated, progestin plus estrogen-treated, and diestrous animals are the same as in spayed animals.
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  • 65
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    The @Anatomical Record 178 (1974), S. 539-549 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Chronic hyperthyroidism was induced in radiothyroidectomized adult albino rats by feeding a diet of 0.3-0.4% desiccated thyroid for four to ten weeks. The left ventricle from control and hyperthyroid animals was examined with the electron microscope after perfusion fixation with 3% phosphate buffered glutaraldehyde and postfixation in 1% osmium tetroxide. No differences were discerned in the appearance of the Golgi zone, glycogen, lipid, lysosomes, sarcoplasmic reticulum, or the sarcomere ultrastructure of the ventricle from hyperthyroid animals compared with untreated animals. Changes were noted in the mitochondria. These included marked hypertrophy without increase in numbers and localized areas of vacuolization and disorientation of the cristae. Apparently these changes are reversible since the ventricular mitochondria of previously hyperthyroid animals allowed to return to a euthyroid state were indistinguishable from those seen in the control group.
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  • 66
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    The @Anatomical Record 178 (1974), S. 567-585 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The endocrine pancreas of the Coturnix quail consists of two major islet configurations. Islets containing B and D cells are found in all four lobes of the pancreas, but islets consisting of A and D cells occur with regularity only in the third and splenic lobes. Pancreatic islets comprise only a small percentage of the tissue volume in the ventral, dorsal and third lobes. In the splenic lobe, however, one or more A islets surrounded by numerous small B islets may constitute more than 50% of the total cellular mass.Secretory granules of the B cells are aldehyde fuchsin-positive and show three distinct profiles at the ultrastructural level. The PTAH-positive A granules are usually round or teardrop shaped and are of uniform electron density. D cells are argyrophilic; their secretory granules are of heterogeneous densities. These cells are located at the peripheries of the B islets, but are freely dispersed in the A islets. At the electron microscopic level, Type IV cells, previously not reported in avian islets, are found mainly in the A islets of this species. This unusual cell type contains granules of differing densities, but, unlike those of the D cell, they are often rod-shaped and biconcave in profile.Because of the distinct segregation of islet types, and the peculiar arrangement of the D and Type IV cells within the two kinds of islets, it is suggested that the Japanese quail may serve as a model for investigations of avian islet function.
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  • 67
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    The @Anatomical Record 178 (1974), S. 599-615 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The intercalated discs of the myocardium from the active and hibernating bat hearts were investigated by means of electron microscopy and use of lanthanum and horseradish peroxidase as tracers. The discs are composed of four zones: intermediate junctions, desmosomes, nexuses, and undifferentiated areas. Of particular interest are the two different types of nexuses. Nexus I without lanthanum displays a 150 Å overall width and an apparent 80 Å intercellular space, ranges from 0.5 to 4.0 μ in length, and is seen in the longitudinal segments of the intercalated disc. With application of lanthanum, however, nexus I shows that the tracer has penetrated a 20 Å gap junction and resembles nexus II. Nexus II with and without lanthanum has a 200 Å overall width and a gap junction of about 20 Å, is generally less than 0.3 μ in length, and is found on the transverse or oblique segment of the intercalated disc. Both nexuses I and II seem to block the passage of peroxidase. The plasma membranes of nexus I may have a different molecular organization from those in nexus II as reflected by their contrasting response to fixation and/or staining. Combinations of the various junctions show that the zones of adhesions (intermediate junctions and desmosomes) are adjacent to the regions of possible lowered resistance (nexus I and II). These findings suggest that adhesion sites insure the proper connection and functioning of the nexuses and support the electrical observations that the heart forms a “physiological syncytium”.
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  • 68
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    The @Anatomical Record 178 (1974), S. 623-630 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: It has often been reported that facial proportions remain constant throughout the fetal period. Such conclusions, however, have been based largely on the erroneous assumption that two dimensions are growing isometrically if one bears a statistically significant linear relation to the the other. In order to test the hypothesis that proportion is independent of time, sagittal histologic sections from 32 human fetuses (12-25 weeks) were analyzed cephalometrically. The linear regression on head length (HL) and the associated coefficient of correlation were calculated for each of a variety of craniofacial measures. In addition, all linear dimensions were transformed so that the size of the anterior cranial base was held constant throughout the series. It was assumed that if shape be constant, all Y-intercepts should be zero, and angular and transformed linear dimensions should show no statistically significant linear correlation with HL. These three criteria were met uniformly by facial and anterior cranial base dimensions, but not by measurements which involved the posterior cranial base. It is concluded, therefore, that in the sagittal plane the second trimester mandible, midface, and anterior cranial base grow isometrically, while the posterior cranial base becomes relatively smaller.
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  • 69
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    The @Anatomical Record 178 (1974), S. 637-645 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Macroscopic and microscopic examination of adipose tissue was carried out in a series of 20 human fetuses, ranging in weight from 380-3032 gm, in an attempt to identify all areas of brown (multilocular) fat development and growth. Brown fat distribution in the human fetus takes the form of a highcollared vest affording coverage to the cervical, thoracic and abdominal viscera. Much of this fat lies deep within the body immediately outside the pleural and peritoneal membranes. the remainder overlies or borders muscles of the shoulder girdle and neck as distinct brown fat deposits deep to the subcutaneous layer of white (unilocular) fat. All brown fat bodies contain unilocular cells but they occur in very small numbers in the brown fat bodies of the posterior cervical triangle, anterior mediastinum and perirenal and suprailiac regions. Brown fat bodies usually develop along the course of large blood vessels and several of them develop direct vascular connections with the liver and kidneys. The total weight of fetal brown fat increases at a rate directly proportional to that of the liver and kidneys up to 2134 gm body weight and to that of the liver beyond this weight.
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  • 70
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The intramural arteries, arterioles and capillaries of the hearts of 23 crossbred pigs, six months old, of Yorkshire and Swedish landrace were presented.The vascular pattern was basically the same in both the ventricular walls. Large branches of two types emerged from the extramural arteries and traversed the myocardial wall, terminating in the subendocardial zone. The largest vessels supplied the papillary muscles and trabeculae carneae. The terminals of these branches formed the subendocardial anastomotic network. No other anastomoses were observed in the ventricular walls. The capillaries had a course parallel to the muscle fibers and anastomosed freely. Most of the interventricular septum was supplied by branches from both the left and the right descending arteries. Only a minor part of the septum was supplied by the anterior and posterior septal arteries.The ventricular vascular pattern of the pig was found to be very similar to that of the human heart. It was concluded that the pig, in contrast to the dog, has ideal attributes for comparative cardiovascular research in man.
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  • 71
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    The @Anatomical Record 178 (1974), S. 667-669 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Projection from medial occipital cortex (area OB) to the nucleus of Darkschewitsch is demonstrated in six Macaca mulatta hemispheres by the technique of Fink and Heimer. Degeneration was present as well in the lateral pons, nucleus lateralis dorsalis, nucleus lateralis posterior, lateral pulvinar and nucleus parafascicularis. Centrum medianum, dorsal lateral geniculate body and interstitial nucleus of Cajal were spared.
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  • 72
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    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The seminal vesicle secretes a variety of substances into semen, ranging from small molecules to enzymes. The formation of protein components of the seminal vesicle secretion was studied in male rats following an injection of leucine-3H. Samples of seminal vesicle were fixed and prepared for light and electron microscope radioautography at intervals ranging between four minutes and two hours after the injection. In specimens prepared four minutes after administration of the precursor, the majority of silver grains overlay the rough endoplasmic reticulum. At subsequent intervals, the proportion of grains over the endoplasmic reticulum declined, and peaks of labeling were observed sequentially over the Golgi apparatus and over secretory vacuoles. The maximal labeling of the Golgi apparatus was attained between 10 and 30 minutes after the injection. Secretory vacuoles acquired their greatest radioactivity 30 minutes following administration of the leucine-3H. Labeled secretions began to appear in the lumen 30 minutes after the injection, and they became heavily labeled by one hour. The results suggest that secretory proteins are synthesized in the rough endoplasmic reticulum and transported rapidly to the Golgi apparatus where secretory vacuoles are formed. The secretory vacuoles migrate to the apical ends of the cells and discharge their contents into the lumen. The transport and release of secretory proteins in the seminal vesicle is unusually rapid and exceeds the rate in many other protein secreting cells, including that of the ventral prostate.
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  • 73
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Proteins, including enzymes such as acid phosphatase, are among a variety of substances secreted into semen by the prostate gland. The formation, intracellular transport, and discharge of protein components of prostatic secretion were studied in the rat ventral prostate following an injection of leucine-3H. Samples were prepared for light and electron microscope radioautography at intervals ranging from four minutes to two hours after the injection. In samples prepared four or ten minutes after administration of the precursor, most of the silver grains overlay the rough endoplasmic reticulum. Beginning 30 minutes after the injection, while label associated with the endoplasmic reticulum was declining, the proportion of grains over the Golgi apparatus began to increase, reaching a maximum in one-hour samples. Secretory vacuoles at the apical ends of the cells became heavily labeled two hours after administration of the leucine-3H. Labeling of secretions in the lumen of the prostatic alveoli was observed in samples taken two hours after the injection. These results indicate that secretory proteins in the prostate are synthesized in the rough endoplasmic reticulum, transported to the Golgi apparatus, and packaged into secretory vacuoles, which move to the apical ends of the cells and release their contents to the lumen. Additional analysis of the pattern of labeling of different elements of the Golgi apparatus suggests that some protein is transported sequentially from Golgi vesicles to stacks of cisternae and finally into Golgi vacuoles. Radioactive secretory proteins move through prostatic cells more slowly than through the seminal vesicle epithelium of the same animals. The main mode of protein secretion in the prostate appears to be a merocrine type, since apical protrusions such as have been suggested to participate in an apocrine form of secretion were observed infrequently and did not become heavily labeled.
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  • 74
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    The @Anatomical Record 180 (1974), S. 597-603 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The minimum period of uterine exposure required by ejaculated boar spermatozoa as a preliminary to rapid capacitation has been determined after natural or surgical deposition of sperm samples directly into the uterine lumen. Twenty-four oestrous gilts were mated or inseminated close to the time of ovulation, and 15, 30, 45 or 60 minutes later, the Fallopian tubes were separated from the uterine cornua. The tubes were flushed at pre-arranged intervals during a second intervention, and the proportion of eggs penetrated and activated examined by phase-contrast microscopy.On the basis of 166 eggs recovered from eighteen mated gilts, a period of uterine exposure as brief as 30 minutes, when followed by a tubal residence of approximately three hours, permitted 30.3% of the eggs to be activated; this proportion increased to 51.6% and 60.5% if the tubes were isolated 45 or 60 minutes, respectively, after mating (p 〈 0.001), as did the mean number of spermatozoa associated with the eggs. When the cornua were separated from the tubes 15 minutes after semen deposition into the uterus of six animals, 11.3% of 62 eggs were fertilized during the ensuing three and one half hours, but very few spermatozoa had reached and/or attached to the eggs in this group.It is concluded that a population of boar spermatozoa potentially capable of effecting fertilization may enter the tubes within 15 to 30 minutes of mating near the time of ovulation, and that such vanguard spermatozoa can activate a proportion of the eggs within a further two to three hours. Thus, from a temporal point of view, the major components of the capacitation process in oestrous pigs are inferred to take place in the Fallopian tubes.
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  • 75
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 180 (1974), S. 645-661 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Five different proteolytic enzymes, trypsin, pronase, collagenase, papain and ficin, were tested for their ability to liberate mononucleated myogenic cells from adult rat muscle. Fragments of leg and thigh muscle from 350-400 gm rats were incubated with enzyme for one hour and mononucleated cells were separated from the partially digested fragments by centrifugation. Myogenic capacity of the isolated cells was tested in culture using procedures known to support differentiation of embryonic rat muscle. Although all the enzymes released viable cells from the muscle, myogenesis in vitro was obtained only from cells liberated by trypsin or pronase. The other three enzymes released fibroblasts, macrophages and fat cells but no presumptive myoblasts. Light and electron microscopic examination of the digested muscle revealed that the enzymatic release of myogenic cells is dependent upon removal of the basement lamina surrounding the fibers. Trypsin and pronase dissolve the basement lamina, whereas collagenase, papain or ficin do not. These findings demonstrate that a population of myogenic stem cells exists in fully mature, non-regenerating adult muscle. The frequency of these cells and the conditions required for their release suggest that they are identical with the muscle satellite cells.
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  • 76
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 180 (1974), S. 681-686 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Collapse of the left lung in adult mice is followed by an increased mitotic incidence (MI) in the right lung which persists for approximately four days after operation. This compensatory increase in MI does not occur if the left thoracic cavity is packed with an implant of cotton wool which prevents hyperinflation of the right lung. The rate of incorporation of labelled thymidine per unit of DNA (RIT) is higher in the right than in the left lung of unoperated animals but after collapse of the left lung there is a reduction in the ratio of right to left in respect of RIT. These differences in RIT do not appear to correspond to changes in the rate at which cells enter DNA synthesis and it is suggested that they are due to differences in vascularisation between the right and left lungs. The compensatory increase in MI which follows unilateral collapse is not due to loss of tissue mass, to tissue damage or to the direct effects of the increased physiological load placed upon the remaining functional tissue. It is suggested that hyperinflation of the right lung causes changes in the rate of blood flow through that part of the organ and that, in consequence, there is a change in the local concentration of metabolites including those whose function is to regulate the mitotic rate.
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  • 77
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 178 (1974), S. 229-241 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Banded spindle-shaped structures consisting of packed cylindrical units were observed among the typical collagen fibrils in the notochord sheath or in the intercellular space between notochord cells of Salmo irideus larvae. The banded spindle-shaped structures showed a regular periodicity ranging from 750-1000 Å and cylindrical structures which appear to be packed in hexagonal arrays so that six cylinders surrounded a central cylinder. Both banded and cylindrical structures appeared to be the same bodies in three dimensions. These banded structures may originate from surrounding collagen fibrils.On the other hand, comb-shaped structures were found between the elastica externa and the collagen fibrils of the notochord sheath in newly hatched S. irideus larvae and in fry. The width of the structures was about 0.25 Å in the widest part. The banding showed a regular periodicity ranging from 500-600 Å. These structures may play a role in adhesion of the elastica externa to the underlying collagen fibrils of the notochord sheath.
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  • 78
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 178 (1974), S. 289-290 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Ultrasound studies of dorsalis pedis artery in 400 feet showed the artery to be absent in 2.25%, i.e., much less frequently than it was commonly claimed. Clearer understanding of this variation and its frequency may facilitate the diagnosis of peripheral circulatory disease.
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  • 79
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 178 (1974), S. 291-527 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 80
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Leydig cells appear in the hamster testis between 12 and 13 days gestation. The cells are round to oval, with prominent lipid droplets, abundant smooth endoplasmic reticulum, large mitochondria with tubular cristae and well developed Golgi complexes. Cells of this type are found in pairs and groups around interstitial blood vessels during the last three days of gestation and up to the fourth day after birth, when regressive changes begin to appear. During the second postnatal week, most cells in the interstitial regions are undifferentiated, with only a few scattered partially differentiated Leydig cells remaining. The time during which fully differentiated Leydig cells are present encompasses the period of sexual differentiation of the reproductive ducts and the critical period for differentiation of sexual behavior.
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  • 81
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The forebrain of the isolated central nervous system of frogs was fixed by freeze substitution and studied with the electron microscope. The extracellular space (ECS) of brains kept for 15-20 min in a physiological salt solution at room temperature varied from an appreciable to a negligible one. In electron micrographs exhibiting a large ECS the tissue elements had a uniform electron density. The EMs with little space featured in some instances a moderate swelling of presynaptic terminals and other tissue elements. Brains kept in a cooled medium or a salt solution with MgCl2 added exhibited invariably an abundant ECS. Treating the brain with a 100 mM KCl solution 5-90 sec before freezing yielded EMs with a contracted ECS and swollen tissue elements, many of which could be identified as dendritic spines. This effect of KCl was in many experiments prevented by bathing the brain in a salt solution containing 10 mM MgCl2 or in a Ca-free solution.
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  • 82
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The influence of different estrogen-progesterone ratios on DNA synthesis in the rat uterus was investigated. Ovariectomized rats were injected subcutaneously daily for three days with either oil, 1 μg estradiol-17β dipropionate or estradiol and 1, 5, 10 or 15 mg progesterone. Tritiated thymidine was administered one hour prior to necropsy. Thymidine indices were determine for both the luminal and glandular uterine epithelia while the total number of labeled nuclei in the stroma was ascertained. In all tissues studied, significantly more nuclei from uteri of rats given only estrogen replicated DNA than from those of the oil-treated controls. While concurrent treatment with estradiol and 1 or 15 mg progesterone did not statistically alter the extent of thymidine incorporation in the luminal epithelium and stroma from that observed following estrogen alone, 5 or 10 mg progesterone given with estrogen significantly suppressed the labeling activity in the luminal epithelium and stroma from that of the estrogen-treated rats. However, the thymidine indices of the glandular epithelium from uteri of rats injected with all combinations of both hormones were significantly lower than that from uteri of estrogen-treated rats. These data indicate that the estrogen-progesterone ratio is important in regulating cell turnover in the luminal epithelium and stroma of the rat uterus but not in glandular epithelium.
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  • 83
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Light microscopic studies using a battery of basic dye stains combined with sialidase and hyaluronidase digestions indicated that the extensive basophilia of the maternal surface of the placental syncytium largely results from the presence of a non-sulfated mucosubstance specifically identified as hyaluronic acid. Ultrastructural examination of dialyzed iron (DI) stained specimens revealed that DI-positive filaments observed along the syncytial surface were removed by hyaluronidase digestion. Staining with the lectins, Concanavalin A or lentil bean hemagglutinin produced an intense and periodic pattern of staining that was not enzyme labile. Incubation of tissue sections in the enzyme solutions or control buffers allowed the lectins to penetrate the syncytial plasma membrane and stain material within the endoplasmic reticulum presumed to be human chorionic gonadotropin. The maternal surface exhibited essentially no reactivity for acid phosphatase but showed strong alkaline phosphatase activity with a periodic staining pattern. With each of the techniques used there was variability in the intensity of staining in different regions along the maternal surface, suggesting that functionally different zones may be identified cytochemically. Only minor differences were observed in the cytochemical reactivity of early compared with term placenta.
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  • 84
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 179 (1974), S. 27-55 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In an effort to elucidate various aspects involving the initiation of development, the morphogenesis of the spontaneously activated egg of the golden hamster was examined at the light and electron microscopic levels of observation. Spontaneous activation of the unfertilized hamster egg occurs upon prolonged incubation within the oviduct, i.e., aging in vivo, and may include the formation of the second polar body and the development of one or several pronuclei. In many instances the activated egg resembles the inseminated ovum at the pronuclear stage of fertilization. Occasionally the activated egg will divide and yields a structure which is morphologically similar to the two-cell stage. Development beyond the two-cell stage was not observed. Even though a number of events exhibited by the aging hamster egg mimic those of the fertilized, many are indicative of cellular degeneration. Such processes include, for example, the aggregation of organelles into fairly homogeneous clusters, the budding of portions of the cortex of the egg containing cortical granules into the perivitelline space, the accumulation of vesicles within the ooplasm and the structural modification of microvilli. All activated eggs, at every period investigated (6 to 66 hours post-ovulation), contained cortical granules.
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  • 85
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A parental (CBAT6T6) lymph node cell suspension was injected into the hind footpad of F1 (CBA × C57BLKs) recipients. The resulting increase in the recipient's popliteal lymph node weight was linearly related on double log plots to the number of parental lymph node cells injected. The node weight response was biphasic including an initial rise, a maximum weight gain at seven to nine days and a gradual decline to normal weight. When the long-lived small lymphocyte population of the donor was labeled with 3H-thymidine, the location, morphology and mitotic activity of labeled cells was followed by radioautography. These cells were most frequently observed in the mid- and deep cortex and the medullary cords of the host node. Very few labeled blast cells were observed in sections or smears and radioautographs of chromosome spreads confirmed the infrequency of donor long-lived small lymphocyte transformation and proliferation. Of the proliferating cells in the host node at the peak of the response, 60-85% were of host origin. These observations and others are discussed, and it is proposed that the host short-lived small lymphocyte accounts for the majority of mitotic cells in the node at the peak of the response.
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  • 86
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Study of the caudal cochlear nucleus of the cat confirms the cochlear origin of synaptic terminals, identified in correlated rapid Golgi and electron microscopic preparations of the octopus cell area (OCA) and the dorsal cochlear nucleus (DCN) in normal cats. Type 1 and type 2 endings on octopus cell somas and basal dendrites, as well as type 1 and type 1a endings of the outer DCN, degenerate following complete ipsilateral cochlear ablations and short survival periods (12, 24, 48, 96 hours). Two distinct patterns of synaptic degeneration occur after short survival times; “dense degeneration” occurs in type 1 endings on octopus cells and several endings of the DCN. Dense terminals that contain tightly packed, but intact vesicles, occur most frequently after a 48-hour survival period. A second type of degeneration, called “flocculent degeneration” occurs in type 1 and type 2 endings of the OCA and in type 1 and type 1a DCN terminals. Between 12 and 48 hours after ablation, the flocculent degeneration involves a continuous breakdown of organelles. Evidence for transneuronal degeneration of octopus cells and DCN granule cells is presented.
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  • 87
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    The @Anatomical Record 179 (1974), S. 517-526 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Some aspects of the basic histological features of the thymus are still not adequately known. The architecture of the heterogeneous organ, like the thymus, can be revealed by a tridimensional reconstruction only. We carried out such reconstruction of the cortex, medulla and network of interlobular septa of the rat thymus. The serial sections of a 10-week-old and of a 5-day-old thymus were projected on a cardboard of a thickness proportional to the magnification of the projection. The outlines of the three studied components were traced and cut off. The superposition of the similar cut-offs yielded a model of each of the three thymic components. The models demonstrated that the current description of the organ is not thoroughly realistic. It was found that there exists bridges of cortex crossing the medulla, whereas buds of medulla are present in the area generally occupied by the cortex. The relationship between the medulla and the cortex is more intricate than currently described. The results revealed that the interlobular septa do not form a network of more or less regular walls designed to divide a lobe into comparable lobules. Instead, this network is irregular, being related to the pathway of the main intrathymic blood vessels.
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  • 88
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The purpose of this investigation was to study the fine structure of pulpal capillaries located in the odontoblastic layer and immediate subjacent zone. The observations were from first molars of white mice sacrificed at five day intervals from 25-90 days. Both capillaries and small vessels with an incomplete smooth muscular coating appeared in the zone subjacent to the odontoblastic layer from 25-60 days. At the same time, capillaries which exhibited intracellular fenestrations in the endothelial wall were located within the odontoblastic layer.From 50-90 days, the capillaries among odontoblasts, especially at the pulpal horns, appeared close to the predentinal surface, and an isolated capillary appeared to extend into predentin and run parallel to the outer surface of the odontoblastic layer for a short distance. At these ages, the capillaries subjacent to the odontoblastic layer also exhibited fenestrations along the thin endothelial walls similar to those observed at earlier ages in capillaries among odontoblasts.
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  • 89
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 180 (1974), S. 1-1 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 90
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Innervation to muscles of the feline perineum was examined by gross dissection of the sacral nerve plexus and quantitation of efferent and afferent myelinated fibers in selected nerves derived from the plexus. In addition, distribution of muscle fiber sizes and muscle spindle content were determined for muscles innervated by the nerves studied.Efferent myelinated fiber populations were bimodal in nerves innervating muscles with many spindles and unimodal in nerves innervating muscles in which few or no spindles were observed. Coccygeus and levator ani muscles had similar numbers of muscle spindles, but the spindles were different in the two muscles based on afferent innervation. In both coccygeous and external anal sphincter muscles, primary spindle endings must be associated with relatively small afferent nerve fibers. The pelvic urethra received more large myelinated afferent fibers than the penis. The three divisions of the external anal sphincter muscle had three distinct populations of muscle fibers, based on size distribution. The homologous bulbospongiosus and constrictor vulvae muscles had different populations of muscle fibers.
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  • 91
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Three groups of mice were standardized to a light-dark cycle with light from 0600 to 1800. One group was fed ad lib; but the other two had access to food for only four hours a day, one during the first part of the light phase and the other beginning at its middle. Two other groups were subjected to a reversed light-dark cycle (light from 1800 to 0600); one of these had access to food for four hours during the first part of the dark phase and the other for four hours beginning at its middle. All the mice previously had been adjusted gradually over a three-week period to these feeding schedules, and then they were maintained on the precise routine described for an additional two weeks. After standardization was completed, subgroups of mice were killed at three-hour intervals over a single 24-hour period. Corneas were removed and prepared, and the mitotic index in the epithelium was evaluated.In all five groups a high-amplitude circadian rhythm was found for the mitotic index, but in all cases this rhythm remained synchronized to the light-dark cycle; only small changes in the phasing of the rhythm resulted from the restricted feeding. These results are contrary to what has been found for a number of other rhythmic variables which do synchronize to such feeding schedules.The findings dispel the misconception that all body functions react in the same fashion to different synchronizors and emphasize that one must not generalize about the effects of feeding or lighting.
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  • 92
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 180 (1974), S. 77-98 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In order to investigate the postnatal growth of the gas exchange apparatus, the lungs of rats aged 1, 4, 7, 10, 13, and 21 days were fixed by intra-tracheal instillation of glutaraldehyde. The analysis and interpretation of the morphological changes observed by light and electron microscopy were based on the results of previous morphometric and autoradiographic studies performed on the same material.The newborn rat has no alveoli, but breathes with smooth walled air channels and saccules, which correspond to the prospective alveolar ducts and alveolar sacs, respectively. The bulk of alveoli are formed between days 4 and 13 by a rapid outgrowth of secondary septa from the primary septa present at birth. The arrangement of elastic fibers during this period suggests that these may play a role in septal outgrowth. Based on ultrastructural observations a model is described for the capillarisation of the secondary septa. Some evidence is given that alveoli may also be formed by outpouchings in the walls of terminal bronchioles.Primary and secondary septa have initially an immature appearance. They both show an apparently double capillary network, whereas the mature interalveolar septum is just wide enough to accommodate a single capillary. Possible mechanisms for this structural transformation which occurs within three weeks after birth are discussed.
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  • 93
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The fathead minnow, Pimephales promelas (Rafinesque), has been laboratory bred and the early embryos staged and described. At 23°C the embryo requires 33 hours to reach the 13-somite stage. This period of early embryonic development has been divided into 12 stages. The description of each of these stages is accompanied by photographs.
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  • 94
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 180 (1974) 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
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  • 95
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    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 180 (1974), S. 111-135 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The surface topography of palatal shelves was examined by scanning electron microscopy prior to and during secondary palate formation in 72 therapeutically aborted human embryos and fetuses ranging in age from 37 days to 12 weeks (post-fertilization). Alterations in epithelial surface appearance were observed in the prospective region of fusion prior to contact between the shelves. First seen as an elliptical area along the anterior portion of the presumptive medial edge, a zone of alteration spread progressively along the anterior four-fifths of the medial edge prior to shelf contact, and continued along the posterior one-fifth of the shelf as fusion proceeded. The altered zone eventually extended onto the oral surface in the middle of the shelf but was restricted to a narrow zone along the medial edge posteriorly. Initially characterized by elongation and “intertwining” of superficial cells, alterations later included cell death, desquamation and possible active migration of surface cells. The shelf epithelium subjacent to the zone of alteration exhibited increased irregularity in thickness and numerous “invaginations” into the underlying mesenchyme. These alterations are thought to reflect intrinsic changes within the shelf and may play a role in the fusion process. Evidence for surface remodeling following fusion was also observed.
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  • 96
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    The @Anatomical Record 180 (1974), S. 281-283 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Using bipolar fine-wire electrodes, we investigated the function of the pectineus muscle. Electromyography revealed that the main function of pectineus muscle is flexion, adduction and medial (not lateral) rotation of the hip joint. These functions suggest that the spasm of this muscle may be important in the cause of deformities in cerebral palsy.
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  • 97
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Mouse blastocysts were grown in vitro and the ultrastructure of resulting egg cylinders was compared with the ultrastructure of egg cylinders isolated from uterus. Egg cylinders grown in vitro had two or three germ layers and were attached to the bottom of the dish through the layer of trophoblastic cells. The entoderm was composed of two cell types intermixed haphazardly: (1) One type had numerous microvilli on the free surface and a large number of dense bodies, autophagic vacuoles, big and small vacuoles and myelin figures in the cytoplasm. (2) The other type had rich, rough endoplasmic reticulum with wide cisternae. The cisternae were filled with fine, granular material similar to that found as a thick membrane separating the entodermal layer from the rest of the embryo. The first type of cell was ultrastructurally similar to cells of the visceral entoderm of egg cylinders isolated from uterus and the second type was similar to cells of the parietal entoderm. The thick basement membrane observed in embryos grown in vitro was similar to Reichert's membrane. Parietal entoderm and Reichert's membrane were never found as separate structures in embryos grown in vitro. It is probable that the entodermal cells in blastocysts differentiate in vitro into both parietal and visceral entodermal cells within the same layer. Mesodermal and ectodermal cells of vitral embryos were similar to such cells in the egg cylinders isolated from the uterus. The cytoplasm was filled with free ribosomes in the form of polysomes and also contained a few profiles of endoplasmic reticulum, well developed mitochondria and Golgi apparatus. Intercellular spaces between mesodermal cells were large and the cells were not attached to one another. Ectodermal cells were tightly packed and inter-connected with numerous desmosomes. The ultrastructure of egg cylinders in vitro and in vivo was similar. Observed differences might be caused by culture conditions and some of them probably represented the changing pattern of differentiation in vitro.
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  • 98
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    The @Anatomical Record 180 (1974), S. 309-329 
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Electron microscopic studies were made of hepatocytes from sham-operated rats, adrenalectomized animals fasted 15 hours, and adrenalectomized rats fasted 15 hours but given a single I.P. injection (10 mg) of cortisone acetate. The objective of this work was to define the earliest morphological response of hepatocytes to injection of a glucocorticoid and to provide additional information on the mechanism of hormone action at the cellular level. Hepatocytes from fasted, adrenalectomized rats contained no glycogen particles and very little smooth endoplasmic reticulum (SER). In addition the rough endoplasmic reticulum was disorganized and showed fewer ribosomes and polysomes than found in liver cells from sham-operated rats. Two hours after glucocorticoid injection glycogen particles were seen in numerous centrilobular cells and some periportal hepatocytes. Elements of SER were associated with the glycogen particles. By 4 hours after hormone injection abundant glycogen was found in all hepatocytes. Centrilobular cells showed dispersed glycogen with extensive tubules of SER associated with the glycogen particles. Periportal hepatocytes accumulated glycogen as dense masses scattered throughout the cytosome. SER occurred mainly at the edges of the glycogen masses. Midlobular cells showed glycogen patterns intermediate between periportal and centrilobular cells; masses of dispersed glycogen with abundant SER occurred within and around the glycogen areas of the cells. Glucocorticoid stimulation also caused cisternae of RER to align in parallel arrays, and more ribosomes and polysomes appeared on membranes of RER than in similar cells from adrenalectomized rats. The interpretation is offered that the glucocorticoid-stimulated proliferation of SER is the morphological expression of induced microsomal enzyme synthesis (glucose-6-phosphatase) known to occur under these hormonal conditions.
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  • 99
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The follicular cells of thyroid glands of intact rats respond to TSH challenge by an intense mitotic stimulation and a higher functional activity as measured by the epithelium height. In hypophysectomized rats the same intense response was observed when the thyroid was challenged immediately after hypophysectomy. However, one week later the mitotic response was almost completely absent and the functional response much weaker. This indicates that, although TSH is the main regulating factor of the functional activity and cell proliferation of the thyroid follicle, its effect is conditioned by additional factors. These factors may originate both from the anterior and/or posterior pituitary, since a significantly higher response was obtained by injecting anterior or posterior pituitary powder during the interval between hypophysectomy and TSH challenge. Prolactin, vasopressin and oxytocin also boosted the mitotic response to TSH. Posterior pituitary powder alone (without TSH challenge) was not mitogenic for the thyroid gland either in intact or hypophysectomized rats, while it was mitogenic for the adrenal glomerulosa. The low thyroid mitotic responsiveness does not reflect a general unspecific effect on mitoses of all cells, since the esophageal epithelium was not similarly affected by hypophysectomy or by replacement therapy.
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  • 100
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Adrenal glands of the domestic duck (Anas platyrhynchos) were fixed in formaldehyde-glutaraldehyde for light and electron microscopical examination. Each gland is encapsulated by a layer of connective tissue and consists of two major secretory cell types, the interrenal cells and the medullary cells. In section, the medullary cells appear as islands of tissue dispersed throughout the gland. The interrenal cells are characterized by numerous lipid droplets and abundant mitochondria having mainly tubular cristae. They have an extensive Golgi apparatus, moderate amounts of smooth endoplasmic reticulum and a lesser amount of rough endoplasmic reticulum. Lipid droplets and mitochondria in interrenal cells were seen frequently in association with the endoplasmic reticulum. Adjacent interrenal cells had numerous regions of pentalaminar fusion and intermediate junctions.Medullary cells were characterized by a large population of electron opaque neurosecretory granules. These cells contained fewer mitochondria and cisternae of endoplasmic reticulum than the interrenal cells. In many cases the medullary cells and interrenal cells were closely juxtaposed and were separated by a thin band of extracellular matrix.
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