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  • 1
    ISSN: 1432-0827
    Schlagwort(e): Osteopetrosis ; Diphosphonates ; Bone Resorption ; Mouse ; Calcium ; Tooth ; Bone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé L'effet de doses quotidiennes, administrées depuis la naissance, de deux types de diphosphonates, à savoir l'éthane-1-hydroxyle-1,1-diphosphonate (EHDP) et le dichlorométhylène diphosphonate (Cl2MDP), sur la croissance et le squelette de souris a été étudié. Les diphosphonates freinent la croissance: les incisives ne font pas leur éruption ou elle est plus tardive. La calcémie est normale. L'administration de Cl2MDP à une dose quotidienne de 10 mg P/kg/jour provoque des modifications squelettiques identiques à celles des souris grises létales atteintes d'ostéopétrose et les animaux meurent après quatre semaines de traitement. Par rapport aux témoins, les souris traitées présentent des os plus étroits, plus denses et plus déformés: les cavités médullaires sont comblées avec de l'os calcifié et du cartilage. La quantité totale de calcium d'un animal n'est pas augmentée par traitement au diphosphonate, par rapport à un témoin de même âge. Chez les souris grises létales et celles traitées aux diphosphonates, la plupart des anomalies est secondaire à une résorption osseuse diminuée. Ces résultats sont commentés en fonction de l'emploi des diphosphonates au cours de remaniements osseux pathologiques augmentés et en fonction du rôle de la résorption osseuse dans le maintien de la calcémie.
    Kurzfassung: Zusammenfassung Mäuse erhielten von der Geburt an tägliche Dosen folgender zwei Diphosphonate: entweder Äthan-1-Hydroxy-1,1-Diphosphonat (EHDP) oder Dichloromethylen-Diphosphonat (Cl2MDP). Es wurde deren Wirkung auf das Wachstum und das Skelet untersucht. Die Diphosphonate verlangsamten das Wachstum, die Schneidezähne brachen nicht oder erst später durch, aber die Höhe des Plasmacalciums blieb normal. Die Verabreichung von Cl2MDP in Dosen von 10 mg P/kg/Tag führt zu Skeletveränderungen, welche denjenigen der „grey-lethal” osteopetrotischen Mäuse gleichen. Die Tiere sterben nach einer Behandlungsdauer von etwa 4 Wochen. Verglichen mit normalen Mäusen von ungefähr gleichem Alter hatten die behandelten Mäuse kleinere, dichtere und mehr keulenförmige Knochen, und die Markhöhlen waren gefüllt mit verkalktem Knochen oder Knorpel. Die Gesamtcalciummenge im Skelet wurde durch die Diphosphonatbehandlung nicht erhöht; dies ergab sich aus einem Vergleich mit der bei normalen Mäusen desselben Alters gefundenen Menge. Es wird vorgeschlagen, daß bei den „grey-lethal” und bei den Diphosphonat-behandelten Mäusen viele der Abnormalitäten als Folge der herabgesetzten Knochenresorption angesehen werden müssen. Die Ergebnisse werden einerseits im Hinblick auf den Gebrauch der Diphosphonate bei pathologischen Bedingungen eines erhöhten Knochenumbaus diskutiert; andererseits werden sie im Zusammenhang mit der Rolle der Knochenresorption bei der Erhaltung des Plasmacalcium-Spiegels besprochen.
    Notizen: Abstract The effect of daily doses from birth of two diphosphonates, namely either ethane-1-hydroxy-1,1-diphosphonate (EHDP) or dichloromethylene diphosphonate (Cl2MDP), on the growth and the skeleton of mice has been studied. Diphosphonates slowed growth, the incisors did not erupt or erupted later, but the level of plasma calcium remained normal. The administration of Cl2MDP at a dose rate of 10 mg P/kg/day leads to skeletal changes that are similar to those observed in grey-lethal osteopetrotic mice, and the animals die after about four weeks of treatment. As compared with normal mice of similar age, treated mice had bones that were smaller, denser and more clubshaped, and the marrow cavities were filled with calcified bone or cartilage. The total amount of calcium in the carcass was not increased by diphosphonate treatment, as compared with the amount in normal mice of the same age. It is suggested that both in the grey-lethal and diphosphonate-treated mice many of the abnormalities are secondary to decreased bone resorption. The results are discussed with respect to the use of diphosphonates in pathological conditions of increased bone turnover and with respect to the role of bone resorption in the maintenance of plasma calcium levels.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 12 (1973), S. 117-124 
    ISSN: 1432-0827
    Schlagwort(e): Mouse ; Calcification ; Metals ; Mast Cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Des souris, ayant reçu par voie intra-veineuse une solution d'acétate de plomb, sont injectés par voie sous-cutanée avec du sulfate de polymixine B. Au niveau de ce dernier point d'injection, on observe des calcifications. L'examen histologique montre une dégranulation des mastocytes, une vaso-dilatation locale ainsi qu'une diffusion d'ions à partir des vaisseaux. Après 24 heures, des ions calcium et phosphate sont présents. En outre. des groupes de souris, pré-injectées par voie intraveineuse avec de l'acétate de plomb, reçoivent des extraits de granules de mastocytes, comportant du phosphate d'histamine, du sulfate de créatinine sérotonine, de l'héparine, du sulfate de chondroitine ou de l'acide hyaluronique. Seules les injections de sérotonine et d'histamine, connues comme vaso-dilatateurs et augmentant probablement la perméabilité capillaire, provoquent des calcifications. Il semble que le rôle des mastocytes dans la calcification soit lié principalement à la production d'une vasodilatation locale, avec perméabilité capillaire augmentée, plutot qu'à une action de liaison initiale des ions métalliques.
    Kurzfassung: Zusammenfassung Nachdem Mäusen Bleiacetatlösungen intravenös eingespritzt worden waren, erhielten die Tiere Polymixin-B-Sulfat subkutan. Dies führte zu Verkalkung an der zweiten Injektionsstelle. Die histologische Untersuchung zeigte eine deutliche degranulation der Mastzellen, eine lokale Vasodilatation und das Austreten von Bleiionen aus diesen Gefäßen 24 Std nach der Injektion konnte eine groß Menge von Calcium- und Phosphationen eindeutig nachgewiesen werden. Weiter wurden Gruppen von Mäusen, die vorher Bleiacetat intravenös erhalten hatten. Bestandteile von Mastzellen-Granula injiziert. Diese bestanden aus Histaminphosphat, Serotonin-Creatinin-Sulfat, Heparin, Chondroitin-Sulfat oder Hyaluronsäure. Unter diesen exogenen Bestandteilen bewirkten nur Serotonin und Histamin eine Verkalkung. Beide sind starke Vasodilatatoren und erhöhen vermutlich die kapillare Permeabilität. Es wird postuliert, daß die Rolle der Mastzelle in der “calcergy” viel eher auf einer lokalen Vasodilatation mit erhöhter kapillarer Permeabilität als auf einer primären Bindung der Metallionen beruht.
    Notizen: Abstract Mice previously injected intravenously with lead acetate solution were injected subcutaneously with Polymixin B Sulphate. This resulted in calcification at the latter injection site. Histological evidence showed marked mast cell degranulation, local vasodilation and the efflux of lead ions from these vessels. At twenty four hours after injection abundant calcium and phosphate ions were readily demonstrated. In addition, groups of mice pre-injected intravenously with lead acetate, were injected with constituents of mast cell granules. These included histamine phosphate, serotonin creatinine sulphate, heparin, chondroitin sulphate or hyaluronic acid. Of these exogenous constituents used, calcification was found only after serotonin and histamine injections, both of which are potent vasodilators and presumbly increase capillary permeability. It is postulated that the role of the mast cell in calcergy may be mainly that of producing local vasodilation with increased capillary permeability rather than the initial binding of metallic ions.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 40 (1984), S. 965-967 
    ISSN: 1420-9071
    Schlagwort(e): Mouse ; calvarial bone ; biphosphonates ; mineral mobilization ; lysosomal enzymes ; calcium release ; inorganic phosphate release ; tissue culture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effect of 3 bisphosphonates, 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP), 3-amino-1-hydroxy-propylidene-1, 1-bisphosphonate (AHPrBP) and azacycloheptylidene-2, 2-bisphosphonate (AHBP), on the release of minerals (40Ca,45Ca, Pi) and enzymes from cultured mouse calvaria was investigated in an organ culture system. HEBP and AHPrBP reduced PTH-stimulated mobilization of calcium and inorganic phosphate without affecting the release of lactate dehydrogenase. In contrast, no significant effect by AHBP on mineral mobilization and lysosomal enzyme release could be registered. In parallel with inhibited mineral mobilization, HEBP and AHPrBP inhibited the release of the lysosomal enzyme β-glucuronidase. A possible cellular mechanism of action of bisphosphonates is discussed in the light of these data.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 35 (1983), S. 755-761 
    ISSN: 1432-0827
    Schlagwort(e): Magnesium ; Mouse ; Mineralization ; Resoprtion ; Osteoclasts ; Bone turnover
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The effect of magnesium (Mg) supplementation on bone metabolism has been studied in the normal young mouse. Weanling male mice were given Mg-supplemented drinking water (5 mM or 32 mM Mg) for 4 weeks. Mineral and skeletal changes were assessed by biochemical methods and by histomorphometric analysis of endosteal bone formation and resorption parameters evaluated on tetracycline double-labeled, undecalcified caudal vertebrae. Magnesium supplementation increased serum and urinary Mg concentrations and bone Mg content. Both the calcification rate and the extent of tetracycline double-labeled osteoid surface increased progressively in Mg-treated mice, whereas the mineralization lag time was shortened. The osteoblastic surface was reduced, leading to a fall in osteoid surface. Stimulation of bone mineralization was associated with a rise in extracellular calcium (Ca) and phosphorus (P) concentrations whereas serum 25-OHD and 1,25(OH)2D levels remained normal. The Mg supplementation increased the number of acid phosphatase stained chondroclasts and osteoclasts and the extent of resorbing surface showing histochemically stained osteoclasts. Although urinary OH-proline increased above normal, Ca, P, and cyclic adenylic acid (cAMP) excretion and phosphate concentration (TmP/GFR) remained normal, suggesting that parathyroid hormone (PTH) secretion was not altered. The trabecular bone volume remained normal, showing that the increased bone resorption was balanced by the stimulated bone mineralization. The results show that Mg supplementation influenced both bone formation and resorption in the young mouse, and that the stimulation of bone mineralization was the result of increased extracellular mineral availability. On the other hand, stimulation of osteoclastic bone resorption appeared to occur independently of PTH or of increased 1,25(OH)2D production. Therefore, this study suggests that Mg may controlin vivo bone metabolism by directly influencing bone resorbing cells activity.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 10 (1972), S. 302-313 
    ISSN: 1432-0827
    Schlagwort(e): Diphosphonates ; Bone resorption ; Mouse ; Pyrophosphate ; Tissue culture ; 45Calcium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Deux diphosphonates, le disodium-éthane-1-hydroxyle-1,1-diphosphonate (EHDP) et le disodium dichlorométhylène diphosphonate (Cl2MDP), inhibent la résorption osseuse, induite par des cellules au niveau de calottes craniennes, cultivées pendant 48 heuresin vitro, lorsque ces substances sont ajoutées au milieu. Le Cl2MDP est plus actif que l'EHDP, à des doses variant 0–16 μg P/ml. Le pyrophosphate et l'imidodiphosphate n'inhibent pas la résorption osseuse à des doses comparables. Lorsque les deux diphosphonates sont injectés à des sourisin vivo avant mise en culture, la résorption osseuse observéein vitro est considérablement réduite: à une dose de 10 μg P/g de poids corporel de Cl2MDP, elle est presque totalement inhibée. Cet effet est rapide et dure plusieurs jours. Les conséquences de ces résultats et la méthode d'essai d'inhibiteurs de la résorption osseuse par la méthode combinéein vivo/ in vitro sont envisagées.
    Kurzfassung: Zusammenfassung Zwei Diphosphonate, Dinatrium-äthan-1-hydroxy-1,1-diphosphonat (EHDP) und Dinatrium-Dichloromethylendiphosphonat (Cl2MDP), hemmen zellbedingte Knochenresorption von Mäuseschädeldächern, welche während 48 Stdin vitro kultiviert worden waren, wenn diese Substanzen dem Nährmedium zugegeben werden. Im Dosierungsbereich von 0–16 μg P/ml ist Cl2MDP wirksamer als EHDP. Pyrophosphat und Imidodiphosphat blockieren die Knochenresorption bei entsprechenden Dosen nicht. Wenn die zwei Diphosphonate Mäusenin vivo injiziert werden, bevor das Explantat hergestellt wird, ist die nachfolgende Knochenresorptionin vitro stark vermindert; bei einer Dosierung von 10 μg P/g Körpergewicht von Cl2MDP ist die Resorption fast gänzlich blockiert. Diese Wirkung erfolgt rasch und dauert während einigen Tagen an. Die Folgerungen aus diesen Ergebnissen sowie das Verfahren, Knochenresorptionshemmer mittels kombinierterin vivo/in vitro-Methode zu prüfen, werden diskutiert.
    Notizen: Abstract Two diphosphonates, disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) and disodium dichloromethyle diphosphonate (Cl2MDP), inhibit cell-mediated bone resorption of mouse calvaria cultivated for 48 hoursin vitro, when the compounds are added to the medium. Cl2MDP is more effective than EHDP over the dose range 0–16 μg P/ml. Pyrophosphate and imidodiophosphate do not block bone resorption at comparable dose levels. When the two diphosphonates are injected into micein vivo before explants are prepared, subsequent bone resorptionin vitro is considerably reduced; at a dose level of 10 μg P/g body weight of Cl2MDP it is almost completely blocked. This effect is rapid and persists for several days. The implications of these results and the method of testing inhibitors of bone resorption by the combinedin vivo/in vitro method are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Calcified tissue international 34 (1982), S. 416-421 
    ISSN: 1432-0827
    Schlagwort(e): Bone blood flow ; Mouse ; Plutonium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The rate at which blood is supplied to several bones in female CBA mice was calculated from18F measurements in bone and blood. Blood flow measurements were compared with plutonium uptake in whole bone and on endosteal and periosteal bone surfaces. The results showed that: (a) the rate at which blood is supplied to bone determines the rate of deposition of plutonium; (b) there is a threshold rate of blood supply below which plutonium is not deposited; and (c) the rate of blood supply determines the density of plutonium deposition on endosteal but not on periosteal bone surfaces. These results are discussed in the light of the current bone blood supply hypotheses.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 109 (1970), S. 46-54 
    ISSN: 1432-0878
    Schlagwort(e): Ovary ; Mouse ; Interstitial cells ; Endocrine tissue ; Innervation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Innervation der interstitiellen Drüse im Ovar der Maus wurde elektronenmikroskopisch untersucht. Die adrenergen Nerven wurden mit Hilfe der Falckschen Methode dargestellt. 1. Fluoreszenzmikroskopie: grün fluoreszierende Varikositäten findet man im Stroma ovarii vor allem in der näheren Umgebung von Gefäßen. Nur selten sind Nervenfasern in Komplexen von interstitiellen Zellen (IZ) zu erkennen. 2. Elektronenmikroskopie: Terminale Nervenfasern mit bekannter Innenstruktur erreichen die IZ von allen Seiten und können unabhängig von den Gefäßen verlaufen. Viele Axone durchsetzen die Basalmembran und treten in enge Beziehung zu interstitiellen Zellen. Dabei bilden sie teilweise kolbenförmige Anschwellungen nach Art von Synapsen, die tief in das Cytoplasma der innervierten Zellen eingebettet sein können. Der synaptische Spalt ist 200 Å breit. Spezialisierte prä- und postsynaptische Membranen kommen nicht vor. Die Bedeutung der Synapsen wird diskutiert.
    Notizen: Summary Ultrastructural studies have been carried out on the innervation of the interstitial gland of the mouse ovary. In addition Falck's fluorescence method was applied. 1. Fluorescence microscopy: In the ovarian stroma green fluorescent nerve fibers are frequently to be found in the surroundings of large and small vessels. Seldom small fibers invade blocks of interstitial cells; however, their final ramification is not discernible. 2. Electron microscopy: Terminal fibers of the autonomic nervous system reach the cells of the interstitial gland from all sides. They may be independent from the course of the vessels. Many axons penetrate the basal membrane and come into close contact with interstitial cells, partly by forming large swellings (boutons), which may be deeply embedded into the cytoplasm of the innervated cell. The synaptic cleft is about 200 Å wide. Specialized pre- and postsynaptic membranes have not been found. The innervated cells show no peculiarities. The possible function of the synapses is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 128 (1972), S. 135-138 
    ISSN: 1432-0878
    Schlagwort(e): Spinal cord ; Mouse ; Myelinated neuronal soma ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Im Thorakalmark (Hinterhornbereich) einer Wildmaus wurde ein kleines Nervenzellperikaryon beobachtet, das vollständig von einer Markscheide umhüllt war. Die Zahl der Markscheidenlamellen variierte zwischen 7 und 12. An einer Stelle konnte ein sogenanntes inneres Mesoperikaryon nachgewiesen werden. Die Bedeutung dieses zufällig erhobenen Befundes ist vorerst noch offen.
    Notizen: Summary In the thoracic cord (posterior horn region) of a wild mouse, we have observed a small nerve cell soma completely enveloped by a myelin sheath. The number of myelin lamellae varied between 7 and 12. In one place, the existence of an inner ‘mesoperikaryon’ could also be shown. The significance of this fortuitous finding has not yet been explained.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 124 (1972), S. 465-478 
    ISSN: 1432-0878
    Schlagwort(e): Anterior pituitary ; Mouse ; in vitro ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Anterior pituitaries of mice were incubated for periods up to four hours in Krebs-Ringer bicarbonate glucose gassed with 95% O2∶5% CO2. The incubated explants survived and retained a fine structure that approximated the condition in situ. The few necrotic cells were sharply localized, and were found to be due to initial mechanical damage to the tissue. Some cells of the six granulated types exhibited slight but significant changes attributable to the liberation from the hypothalamic control: in LTH cells there was a release of preexisting granules and a development of cell organelles, whereas in other cell types there was an inhibition of release of granules and an enhanced digestion of the accumulated granules by the lysosomal system. Follicular cells responded uniquely to the changed environment by hypertrophy of the cytoplasm and were found to phagocytize cell debris. A part of non-epithelial elements of the gland showed a tendency to modulate cytologically.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 131 (1972), S. 329-346 
    ISSN: 1432-0878
    Schlagwort(e): Olfactory mucosa ; Mouse ; Glands of Bowman ; Light and electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Das erste Auftreten der Glandulae olfactoriae in der olfaktorischen Region der Maus wird beschrieben. Die Struktur der Bowmanschen Drüse und ihre topologische Beziehung zu den übrigen zellulären Elementen im Riechepithel wird untersucht. Die Bedeutung des Sekrets für die Bildung des Deckhäutchens wird diskutiert. Die Bowmanschen Drüsen der Maus erreichen im letzten Viertel des intrauterinen Lebens die Lamina propria des Riechepithels. In den Endstücken finden sich dunkle, sekretreiche und helle, sekretarme Zellen. Die sezernierenden Zellen der Bowmanschen Drüsen sind nicht auf die Lamina propria beschränkt, sondern erstrecken sich bis in die untersten Anteile des Kernlagers im Riechepithel. Beim Austritt der Bowmanschen Drüsen aus dem Riechepithel in die Lamina propria konfluieren die Basalmembranen dieser Gewebeanteile miteinander. Die gemeinsame Basalmembran kann sich noch eine Strecke weit bis in den normalen Interzellularraum zwischen Drüsen- und Riechepithelanteilen einsenken. In den apikalen Anteilen des Riechepithels wird der Ausführungsgang von den benachbarten Sinnes- und Stützzellen nur durch eine normal breite Interzellularfuge getrennt. Im Ausführungsgang der Bowmanschen Drüse finden sich dunkle und helle auskleidende Zellen. Die durch Desmosomen miteinander verbundenen Epithelzellen der Ausführungsgänge zeigen Zeichen einer Sekretion. Die periphersten Ausläufer des Ausführungsgangepithels erstrecken sich lediglich bis in das Terminalplattenniveau der Stützzellen, mit denen sie sich durch desmosomenartige Kontaktzonen verbinden. In der Verlängerung der Ausführungsgänge wird das Lumen peripher des Terminalplattenniveaus von den apikalen Stützzellanteilen und deren Mikrovilli sowie von den obersten Anteilen der Dendriten, von den Riechköpfen und den Sinneshaaren der Rezeptorzellen umgrenzt. Im Lumen der Ausführungsgangverlängerung finden sich im Bereich des olfaktorischen Saumes flächenhafte Ansammlungen von Sekret. Das Sekret im intervillösen Raum des olfaktorischen Saumes zeigt eine besondere Affinität zu den Membranen der peripheren Sinneszellausläufer. In der intrauterinen Lebensphase ließ sich bisher kein Deckhäutchen feststellen. Die austrocknende Wirkung der Luft auf das Sekret der Bowmanschen Drüsen wird als Entstehungsmechanismus für das Deckhäutchen in Erwägung gezogen.
    Notizen: Summary First appearance, structure and topological relations of Bowmans' glands in the regio olfactoria of white mice are described. The importance of these glands for the formation of the terminal mucous cover of the olfactory epithelium is discussed. In the last quarter of intrauterine life the glands of Bowman reach the lamina propria. In the terminal portion of the glands dark cells with many secretory droplets and pale cells with only a few of them can be seen. Secretory active cells are localized in the basal part of the olfactory epithelium as well. When entering the lamina propria the irregular wide basement membrane of the glands joins that one of the epithelium. It is possible to follow up this joined basement membrane for a short distance between the glands and the cells of the olfactory epithelium. Peripheral to the very basal part of the olfactory epithelium there is no basement membrane around the glands' tissue. Receptors and sustentacular cells are separated from the gland only by a normal intercellular space. The epithelium of the ducts consists of dark and light cells as well. They are connected with the sustentacular cells by desmosomelike contacts. In its prolongation the lumen of Bowman's duct is lined by the apical portions of the sustentacular cells and their microvilli, and by dendrites, olfactory vesicles, and sensory cilia of the receptor cells. In the region of cilia and microvilli one can see masses of secretion which have confluenced. In the intervillous space its special affinity to the receptor's membranes is evident. During the intrauterine phase of life no terminal mucous cover could be demonstrated. The drying effect of the air as a possible reason for the origin of the terminal mucous cover is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 150 (1974), S. 323-329 
    ISSN: 1432-0878
    Schlagwort(e): Spermiogenesis ; Mouse ; Multinucleate spermatids ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Electron microscope studies of the testes of five inbred and three outbred mouse strains show that the usual frequency of multinucleate spermatids is between one and two percent. In C57 BL/6J and A/Gr however it is higher (4–5%). The frequency of the shared acrosome condition, which would lead to the formation of an abnormal sperm, is 1.3 per thousand.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 138 (1973), S. 155-169 
    ISSN: 1432-0878
    Schlagwort(e): Spermiogenesis ; Mouse ; Multinucleate spermatids ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This ultrastructural study confirms and extends the light microscope findings of Bryan (1971) concerning the presence and developmental fate of multinucleate spermatids. Four main classes of cells: uninucleate-individual, uninucleate-conjoined, multinucleate-conjoined, and multinucleate-individual, were identified along with a few instances of more complex syncytial organizations. When the respective nuclei in a given multinucleate are far enough apart, each develops autonomously but in synchrony with its neighbors. When nuclei are intimately associated, the “normal” pattern of spermiogenesis may be altered, giving rise to highly bizarre spermatozoa. Commonly, a single Golgi complex serves a pair of nuclei and gives rise to a “T-shaped” acrosome which binds the nuclei together. During the ensuing nuclear elongation phase, such units are invested by a single manchette. Pairs of axonemes within a common plasma membrane have also been encountered. These ultrastructural findings indicate that multinucleate spermatids are true components (not artifacts) of the seminiferous epithelium of normal animals. The presence of such cells and the unusual developmental consequences which can arise as a result of the multinucleate state must be taken into account when evaluating the course of spermatogenesis in cases of mutation- or chemically-induced infertility.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 136 (1973), S. 263-275 
    ISSN: 1432-0878
    Schlagwort(e): Vaginal epithelium ; Cell differentiation ; Mouse ; Estradiol sensitive antigen ; Immunocytology, Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of an antigenic material specific for the cervicovaginal epithelium (CVA) was studied in the vaginal epithelium of the adult mouse with immunofluorescence and immunoferritin techniques. The antigen localization has been correlated to the fine structure of the vaginal epithelium in various states of functional activity. The antigen distribution in adult ovariectomized mice and in ovariectomized mice treated with estradiol was compared with that in normal cycling mice. CVA was found to be associated with the exterior of the cell membrane of vaginal epithelium cells, being part of the glycocalyx. Two cell types, mucous or keratinized, are derived from the germinative cell layer of the vaginal epithelium, depending on the hormonal environment. Mucous cells with morphological features that characterize cells about to cornify have been demonstrated. Fluorescence as well as ferritin particles, indicating the presence of antigen-antibody complexes, were seen within the mucous droplets of the mucous cells. The CVA production is apparently connected with vaginal mucus formation. The CVA distribution in the adult vaginal epithelium is discussed in relation to the distribution demonstrated earlier in the cervicovaginal epithelium of neonatal mice.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 146 (1973), S. 319-328 
    ISSN: 1432-0878
    Schlagwort(e): Hypothalamus ; Mouse ; Arcuate neurons ; Nucleolus-like bodies ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The arcuate nucleus of untreated (control) and castrated adult mice was studied with the electron microscope. Nucleolus-like bodies (NLB) were found in the cytoplasm and occasionally in the dendrites of arcuate neurons. NLB were spherical or ovoid, 0.7–1.5µm in diameter; they were composed of granules 100–150 Å and 200 Å in diameter, and filaments ∼70 Å in diameter. NLB were frequently associated with free ribosomes and cisternae of the rough endoplasmic reticulum. Light microscopic studies with basic dyes and enzymatic digestions showed that these bodies contained some RNA. There was no significant change in the number of NLB in castrated animals.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 106 (1970), S. 498-515 
    ISSN: 1432-0878
    Schlagwort(e): Thymus ; Epithelial cells ; Differentiation ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The foetal and post-natal development of the mouse thymus was studied with the electron microscope paying particular attention to the differentiation of the epithelial cells. At about 13 days' gestation, the thymus was composed principally of undifferentiated epithelial cells and some lymphoblasts. The latter accumulated rapidly but did not show much evidence of mitotic activity until after the development of differentiated “cortical” epithelial cells which appeared during the 15th day of gestation. Further differentiation of epithelial cells did not occur until near term when medullary “cystic” epithelial cells appeared, and post-natally when small Hassall's corpuscles were developed. Undifferentiated and dividing epithelial cells were seen in the medulla and were present in all postnatal animals examined.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 154 (1974), S. 321-327 
    ISSN: 1432-0878
    Schlagwort(e): Pituitary ; Mouse ; Pars intermedia ; Adrenoglomerulotropin ; Morphometric cytology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ultrastructural changes in the pars intermedia of the mouse pituitary caused by dietary sodium deprivation were investigated quantitatively. Of the six classes of organelles and inclusions selected for analysis in the pars intermedia cells, only the mitochondria showed no significant changes, while all of the remaining classes showed statistically significant changes. The most conspicuous changes were an abrupt decrease in the number of secretory granules and the appearance of parallel arrays of rough endoplasmic reticulum. The Golgi apparatus also showed hypertrophy accompanied by newly formed granules. The number of vesicles increased temporarily and then decreased. These findings indicate that dietary sodium depletion, a stimulus to greater aldosterone secretion, causes significant changes in the pars intermedia cells within 3 days, and these signs of hyperfunction last up to 5 days. The present study suggests a possible new role of the pars intermedia in the regulation of aldosterone secretion in response to dietary sodium deprivation in the mouse.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 122 (1971), S. 488-502 
    ISSN: 1432-0878
    Schlagwort(e): Median eminence ; Mouse ; Growth and development ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The development of the external zone of the median eminence of the mouse was studied in the electron microscope. The examination follows the development of the embryo from the 15th day of the gestation period and the juvenile growth until 24 days of age. Single terminals of the tubero-infundibular neurons of the external zone were found to extend to the outer basement membrane of the perivascular space of the portal primary capillary plexus in the 16 day-old embryo. In the 18 day-old embryo a narrow external zone has developed. Organization of the external zone into the adult pattern is accomplished at the age of three to four weeks. Small agranular as well as large granular vesicles are present in the tubero-infundibular nerve terminals even in the 16 day-old embryo. Changes in the organization of the nerve endings along the outer perivascular basement membrane in relation to the ependymal vascular feet were considered.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 18
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 124 (1972), S. 387-405 
    ISSN: 1432-0878
    Schlagwort(e): Adenohypophysis ; Mouse ; Follicular cells ; Marginal cells ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Follicular cells in the mouse adenohypophysis were studied electron microscopically. These elements appear to be very similar to the marginal cells that delineate both sides of the hypophyseal cleft. The mouse differs from most other species in that the follicular cells in the pars distalis and the marginal cells look completely inactive in young, intact animals. This makes the mouse exceptionally favorable for correlating morphological changes in the cells of both types with changes in the physiological state of the animal. Different treatments applied in the present investigation all induced morphological reactions in the follicular and/or marginal cells; these reactions were generally similar. Thus, morphological changes in the follicular or marginal cells should be considered as general phenomena accompanying many changes in the physiological state of the animal, rather than as a specific result of the treatment applied. In three experiments, the follicular and marginal cells were involved in the digestion of waste material from other cells. It is suggested that the morphological changes in the other experiments should also be interpreted as signs of such an activity. In the pars tuberalis of the young, intact mouse the follicular cells may show characteristics that in the pars distalis are found only under experimental conditions. Therefore, the follicular cells in this part of the hypophysis are probably in an active state.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    ISSN: 1432-0878
    Schlagwort(e): Tracheo-bronchial mucosa ; Amine-storing (enterochromaffin-like) cells ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The tracheo-bronchial mucosa of the mouse has been found to contain an extensive system of argyrophilic epithelial cells. In the trachea the cells morphologically resemble enterochromaffin cells. Normally, these enterochromaffin-like cells contain no fluorogenic amine, as revealed by the Falck-Hillarp formaldehyde technique. On the other hand the cells have the capacity to take up and decarboxylate 3,4-dihydroxyphenylalanine (DOPA) or 5-hydroxytryptophan (5-HTP); the amine formed is stored in the cytoplasm in a reserpine-sensitive store. This capacity to produce and store amines under experimental conditions may reflect the presence in the tracheal enterochromaffin-like cells of an amine which can not be demonstrated with available fluorescence histochemical techniques. In the electron microscope the tracheal enterochromaffin-like cells were identified by a positive argyrophil reaction and by their capacity to accumulate radioactivity after administration of 3H-DOPA or 3H-5-HTP as revealed by autoradiography. The radioactive labelling was associated with cytoplasmic electron-dense granules (800–1000 Å), suggesting that the amine formed was stored in these granules. Accordingly, the granules stained argentaffin after DOPA-pre-treatment of the animal. It is suggested that, like similar cells in the gastric mucosa, these argyrophilic enterochromaffin-like cells constitute an endocrine system in which amines are of cytophysiological importance.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 20
    ISSN: 1432-0878
    Schlagwort(e): Hypophysis ; Mouse ; Rostral zone ; Intermediate lobe ; Corticotrophic cells ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The rostral zone of the intermediate lobe of the mouse hypophysis can clearly be distinguished from the other lobes of the adenohypophysis, especially from the pars tuberalis and the remainder of the intermediate lobe. It consists almost exclusively of corticotrophic cells which show reactive changes after adrenalectomy. The hypophysial stalk is entirely surrounded by this zone; laterally it forms large cell aggregations which extend dorsally as thin cell strands. The corticotrophs are also found within the hypophysial stalk which they invade along the blood vessels; frequently they are dispersed among the typical cells of the intermediate lobe, especially along the neural lobe and the hypophysial cleft.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 130 (1972), S. 249-261 
    ISSN: 1432-0878
    Schlagwort(e): Chromaffin tissue ; Ganglion cervicale uteri ; Mouse ; Light and electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Das chromaffine Gewebe im Ganglion cervicale uteri der Maus wurde licht- und elektronenmikroskopisch in verschiedenen Funktionsstadien des Genitale untersucht. Die Befunde decken sich weitgehend mit den bisher bekannten Beobachtungen an extraadrenalem, chromaffinem Gewebe anderer Lokalisation. 1. Das chromaffine Gewebe besteht aus granulahaltigen Paraganglienzellen und Hüllzellen, die Schwannschen Zellen gleichen. 2. Die Granula der Paraganglienzellen sind sehr kontrastreich und von einer Membran umhüllt, die größeren Abstand von ihrem dichten Inhalt haben kann. 3. Gelegentlich sind die Paraganglienzellen mit Zilien ausgestattet. 4. Zellen mit wenig Granula haben ein kräftiger ausgebildetes rauhes endoplasmatisches Retikulum als Zellen mit hohem Granulagehalt. 5. Die paraganglionären Zellen haben keine besondere Beziehung zum Gefäßsystem. 6. Die Paraganglienzellen stehen mit Nervenendingungen durch Synapsen in Kontakt, die sowohl überwiegend synaptische Bläschen als auch überwiegend „dense core vesicles” enthalten können. Sie scheinen also sowohl durch cholinerge als auch durch adrenerge Innervation kontrolliert zu werden. 7. Unterschiede in der Ultrastruktur der Paraganglienzellen konnten nur zwischen ausgewachsenen und infantilen Tieren festgestellt werden. Letztere haben einen höheren Anteil an Zellen mit wenig Granula. 8. Die Befunde scheinen für eine lokale endokrine Beeinflussung der Nervenzellen des Ganglion cervicale uteri durch Abgabe von Katecholaminen aus den Paraganglienzellen zu sprechen.
    Notizen: Summary The chromaffin tissue in the ganglion cervicale uteri of mice was investigated in different functional stages of their reproductive system by light and electron microscopy. The observations correspond to the findings obtained in extra-adrenal chromaffin tissue localized in other regions. 1. The chromaffin tissue consists of granule containing paraganglionic cells and of surrounding cells that resemble Schwann cells. 2. Occasionally the paraganglionic cells possess cilia. 3. The granules in the cytoplasm of paraganglionic cells are very electron dense and are enveloped by a membrane that forms a vesicle with a diameter either corresponding to that of the granule or considerably larger than the latter. 4. Cells with little granules have a better developed rough endoplasmic reticulum than cells with a great number of granules. 5. The paraganglionic cells have no special relationships to blood vessels. 6. The paraganglionic cells are innervated by synapses that possess synaptic vesicles and by synapses that show accumulations of dense core vesicles. The paraganglionic cells seem to be under the control of cholinergic and adrenergic innervation. 7. Differences of ultrastructure of the paraganglionic cells were seen only between adult and infantile animals. The latter have a greater number of cells containing only a small quantity of granules. 8. The findings suggest the hypothesis of a local endocrine influence of the paraganglionic cells on the neurons of the ganglion cervicale uteri by release of catecholamines.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 133 (1972), S. 559-569 
    ISSN: 1432-0878
    Schlagwort(e): Cervicovaginal anlage ; Estradiol sensitive antigen ; Mouse ; Cell differentiation ; Immunocytology ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cells of the cervicovaginal epithelium of neonatal mice underwent morphological changes in response to estradiol injection. On the luminal border, estradiol treatment caused development of distinct microvilli and a prominent surface coat of delicate filamentous material. Very deep nuclear folds appeared, and the border between adjacent cells became strongly interdigitated. The cells developed a pronounced smooth and rough endoplasmic reticulum, and dark-stained membrane-bounded granules accumulated in the apical part of the cells. Estradiol promoted increased production of an antigenic material specific for the cervicovaginal epithelium (CVA). Immunofluorescence studies demonstrated CVA in the most apical part of the cells, in the extracellular material on the epithelial surface, and in the intercellular spaces between adjacent epithelial cells. This was confirmed by immunoferritin methods, which revealed that the antigen was localized to the surface coat and to material adhering closely to the exterior of the cell membrane, the part facing the lumen and also the part facing intercellular spaces. Within the cells, ferritin tagging was recognized around the membranes enclosing the dark-stained granules in the apical part of the cells and also on the inside of the luminal cell membrane. This is so interpreted that CVA acquires its antigenic properties when passing out from the dark-stained granules through the surrounding envelope. CVA apparently forms part of the glycocalyx of the cervicovaginal cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 140 (1973), S. 445-449 
    ISSN: 1432-0878
    Schlagwort(e): Cecum, Colon ; Mouse ; Glycocalyx ; Intestinal microorganisms ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the cecal epithelium of the mouse resembles that of more distal parts of the colon. A brief discussion is presented of the possible significance of apical cytoplasmic granules to the glycocalyx and of the close association of microorganisms with the lining epithelium.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 106 (1970), S. 69-78 
    ISSN: 1432-0878
    Schlagwort(e): Pancreatic Islets ; B-Cells ; Mouse ; Tubular Bodies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Tubular bodies of varying length and thickness are found in the cytoplasm of pancreatic islet B-cells of obese-hyperglycemic mice and a few of their lean litter mates. Most of these bodies are elongated with tapered ends. There are also some rounded or peculiarly formed variants. They are composed of numerous small electron dense tubular units, often in parallel arrangement. The tubules are embedded in a moderately dense matrix and their interior shows also moderate density. Smaller or larger electron opaque rounded particles are seen in some of the cytoplasmic bodies. Tubular bodies sometimes occur in association with mitochondria, indicating that they might be derived from these cellular organelles. Though the chemical composition and significance of the tubular bodies still are unknown, mitochondrial changes, possibly related to altered metabolic activity, are suggested to form the basis of their development.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 148 (1974), S. 381-396 
    ISSN: 1432-0878
    Schlagwort(e): Placenta ; Mouse ; Syncytium ; Morphogenesis ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé L'origine embryologique des constituants cytologiques de la barrière placentaire chez la Souris a été mise en évidence du 8ème au 11éme jour de la gestation et la séquence des phénomènes favorisant la formation d'un syncytium trophoblastique, précisée. La barrière placentaire trilaminaire a une double origine: la couche interne provient du trophoblaste chorionique, la couche médiane syncytiale comme la couche externe dérivent du trophoblaste ectoplacentaire. Le stimulus initial de la différenciation semble résulter au 9ème jour du contact entre le trophoblaste chorionique et le mésoderme allantoïdien. Quelques heures après, on observe la réaction des cellules chorioniques, caractérisée par une augmentation importante des nucléoprotéines cytoplasmiques, puis l'apparition de globules lipidiques et enfin des propriétés de motilité. Ces cellules établissent des jonctions complexes avec le trophoblaste ectoplacentaire indifférencié qu'elles côtoient. En même temps, le métabolisme nucléaire de ces cellules ectoplacentaires semble modifié. Ultérieurement, au 10éme jour de la gestation, la disparition des membranes plasmiques latérales de ces cellules, conduit à la formation d'un syncytium par fusion de cellules au même stade d'évolution.
    Notizen: Summary The morphogenesis of the different layers forming the mouse placental barrier is described during the 8th to 11th day of gestation. The timing and events leading to the formation of the syncytiotrophoblast are analyzed. Two different processes lead to the formation of the hemotrichorial placental membrane: the internal layer is formed by the chorionic trophoblast, both the intermediate syncytial layer and the external cytotrophoblast layer are derived from the ectoplacental trophoblast. The differentiation of the placental barrier begins on the 9th day of gestation by the establishment of contact between the chorionic trophoblast and the allantoic mesoderm. A few hours later, the chorionic cells show a considerable increase in cytoplasmic nucleoproteins and lipids and become ameboid. Complex cell-junctions differentiate between these chorionic cells and the adjacent ectoplacental trophoblast. On the 10th day of gestation the lateral cytoplasmic membranes disappear leading to the formation of a syncytium.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 118 (1971), S. 310-314 
    ISSN: 1432-0878
    Schlagwort(e): Pineal ; Mouse ; Glycogen ; Diurnal changes ; Quantitative histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The amount of glycogen in pineal cells of 60-day-old male dd-mice was estimated at various times of the day by means of a quantitative histochemical method. The level of glycogen stores varied periodically in correlation with the environmental light-dark cycle, being lowest at the end of the daily dark period and highest at the end of the daily light period. The size of pineal cells also varied diurnally, being largest at 9 AM, two hours after the beginning of the daily photoperiod, and smallest at 9 PM, two hours after the end of the daily photoperiod; however, these changes were less marked than those in glycogen level. The changes in cell size were delayed by a few hours as compared with changes in glycogen stores. In blinded male mice of the same age, neither pineal glycogen level nor pineal cell size varied in response to diurnal lighting.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 118 (1971), S. 525-531 
    ISSN: 1432-0878
    Schlagwort(e): Hypophysis ; Mouse ; Pars distalis ; STH cells ; Hepatomas
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An electron microscopic analysis was performed on the pars distalis of the hypophysis of mice bearing transplanted hepatomas. Normal mice served as controls. In animals bearing a fast growing as well as in those bearing a slow growing hepatoma, the STH cells presented changes indicating increased release and synthesis of its secretory product. These changes can be summarized as follows: 1) Increased number of granuledepleted STH cells which were very irregular in size and shape. 2) Very irregular and sometimes bizarre nuclei. 3) Plasma membranes irregular and convoluted. 4) Increased quantity of endoplasmic reticulum which appeared sometimes dilated and contained material of varying electron density. 5) Abundant, irregular and frequently ramified mitochondria. 6) Hypertrophic Golgi system with increased number of microvesicles. 7) Increased number of large lysosomes of different type. 8) Increased number of fat droplets.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 118 (1971), S. 214-220 
    ISSN: 1432-0878
    Schlagwort(e): Pineal cells ; Mouse ; Glycogen ; Quantitative histochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Effects of continuous lighting on glycogen in pineal cells of the mouse were histochemically investigated, qualitatively and quantitatively. In continuous lighting, glycogen stores in pineal cells show a striking increase during the first three days. The glycogen level rises almost fourfold in 1 day of lighting and reaches a peak at 2 days. At 3 days it begins to decrease slightly. After 3 days the glycogen level decreases gradually until it returns almost to normal in 3 weeks. Continuous lighting causes a decrease in the size of pineal cells, and the decreased size of the cells remains almost constant throughout lighting. In blinded mice, neither glycogen stores in pineal cells nor sizes of pineal cells are affected by continuous lighting.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 129 (1972), S. 188-195 
    ISSN: 1432-0878
    Schlagwort(e): Thymus ; Mouse ; Mitosis ; Circadian rhythm
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The mitotic and pyknotic indices were calculated over a period of 24 hrs in four different zones of the mouse thymus (Balb/C). Counts were based on 1 micron sections of Epon-embedded tissue. This technique gives a more accurate mitotic index than has been calculated in the past because mitotic figures in the prophase stage are more easily recognizable. Mitotic as well as pyknotic index showed a distinct diurnal rhythm in the subcapsular zone, the rhythm being less distinct towards the medulla, where no significant diurnal fluctuations were demonstrated. It was shown that the index variations could be correlated to significant variations in the mitotic time.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 139 (1973), S. 201-215 
    ISSN: 1432-0878
    Schlagwort(e): Median eminence ; Mouse ; Ontogenesis ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Les fibres nerveuses renfermant des vésicules granuleuses et des vésicules de type synaptique apparaissent dans l'éminence médiane de foetus de 14 jours. Dés le 18è jour foetal, de véritables terminaisons nerveuses sont au contact des capillaires du plexus intercalaire, constituant une charnière neurohémale. Les anses intrainfundibulaires commencent à pénétrer dans l'éminence médiane à la naissance mais ce n'est que chez des souris de 5 jours qu'elles deviennent très nombreuses. — Nous discuterons sur des critères morphologiques, de la possibilité d'un contrôle hypothalamique sur l'adénohypophyse avant la naissance.
    Notizen: Summary Nerve fibers containing granular vesicles and vesicles closely resembling synaptic vesicles appear in the median eminence of 14 days old mouse fetuses. At 18th fetal day true nerve endings have been observed which are located close to the capillaries of the superficial plexus forming a neurovascular link. The capillary loops penetrate into the median eminence at the time of parturition but only in 5 days old mice they can be observed more frequently. — On the basis of the morphological observations presented the question is discussed whether the hypothalamus can influence pituitary hormone secretion before birth.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 139 (1973), S. 217-236 
    ISSN: 1432-0878
    Schlagwort(e): Subcommissural organ ; Mouse ; Mucopolysaccharides ; Acid phosphatase activities
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In mice most of the ependymal cells of the subcommissural organ (SCO cells) are densely packed with dilated cisternae of the endoplasmic reticulum (ER) containing either finely granular or flocculent materials. The well developed supra-nuclear Golgi apparatus consists of stacks of flattened saccules and small vesicles; the two or three outer Golgi saccules are moderately dilated and exhibit numerous fenestrations; occasional profiles suggesting the budding of coated vesicles and formation of membrane-bound dense bodies from the ends of the innermost Golgi saccules are seen. A few coated vesicles and membrane-bound dense bodies of various sizes and shapes are also found in the Golgi region. The contents of the dilated ER cisternae are stained with periodic acid-silver methenamine techniques. In the Golgi complex the two or three inner saccules are stained as deeply as the dense bodies, and the outer saccules are only slightly stained. The stained contents of ER cisternae are more electron opaque than those of the outer but less opaque than those of the inner Golgi saccules and the dense bodies. Acid phosphatase activities are localized in the dense bodies, some of the coated vesicles in the Golgi region, and in the one or two inner Golgi saccules. On the basis of these results the following conclusions have been reached: (1) In mouse SCO cells the finely granular and the flocculent materials in the lumen of ER cisternae contain a complex carbohydrate(s) which is secreted into the ventricle to form Reissner's fiber; (2) the secretory substance is assumed to be synthesized by the ER and stored in its cisternae, and the Golgi apparatus might play only a minor role, if any, in the elaboration of the secretory material; (3) most of the dense bodies in the mouse SCO cells are lysosomal in nature instead of being so-called dark secretory granules.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 137 (1973), S. 167-175 
    ISSN: 1432-0878
    Schlagwort(e): Leydig cells ; Mouse ; Ring-shaped nucleolus ; Endoplasmic reticulum ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Many mature Leydig cells of adult mice contain annular nucleoli. In the cytoplasm of these cells, there is an abundance of agranular endoplasmic reticulum and its modifications, i.e. membranous whorls and double-walled tubules. By contrast, the cytoplasm of Leydig cells with compact nucleoli shows abundant free ribosomes and granular endoplasmic reticulum. It is assumed that the granular endoplasmic reticulum shifts to the agranular endoplasmic reticulum and its modifications during the differentiation of the Leydig cell. For the maturation of the Leydig cell the annular nucleoli may play an important role.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 137 (1973), S. 159-166 
    ISSN: 1432-0878
    Schlagwort(e): Ovum ; Mouse ; Membranes ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ultrastructural studies have revealed the presence of unusual membrane complexes within developing mouse oocytes. These structures, most obvious 18 days post fertilization, are found in the nucleus or cytoplasm of cells in meiotic prophase. The complexes, usually found in small groups, are characterized by a slightly bowed appearance, and a thin middle section that is vesiculated at each end. At high magnification the middle section exhibits a pentalaminar structure similar to tight junctional complexes, while the looped membranes of the vesiculated ends are trilaminar in appearance. In addition to being free in the nucleoplasm or cytoplasm, the complexes are also seen in continuity with the inner and outer leaflets of the nuclear envelope, and with typical membranes forming cytoplasmic tubular systems. The possible formation of these complexes from blebs or vesicles derived from the nuclear envelope is presented and the role that these structures may play in developing oocytes is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 140 (1973), S. 77-89 
    ISSN: 1432-0878
    Schlagwort(e): Intercellular junctions ; Neonatal liver ; Mouse ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Au cours du passage de la vie foetale à la vie postnatale, on note, dans le foie de souris, l'apparition d'associations jonctions-organites cellulaires. Celles-ci cont de deux types: associations desmosomes-organites et associations nexus-organites. 1.Associations nexus-organites. Le long de la «gap junction» sont étroitement accolés, uni ou bilatéralement, divers organites: mitochondrie(s), subsurface cisterna(e), peroxysome(s) ou lysosome. Ces associations n'apparaissent qu'entre le 21ème jour de la gestation et le ler jour post-natal, période à partir de laquelle ils disparaissent au profit d'associations desmosomes-organites cellulaires. Un nouveau type de structure s'associe dans le foie aux membranes plasmatiques: il s'agit des saccules ergastoplasmatiques ou subsurface cisternae. 2.Associations desmosomes-organites. Dans ces complexes, les tonofilaments desmosomiques entrent étroitement en contact avec la paroi des organites cellulaires associés: mitochondrie ou peroxysome. Déjà présents au 13ème jour de la gestation, ces structures s'observent plus fréquemment à partir du ler jour post-natal. La signification de ces associations reste à déterminer, d'autant plus que leur présence a déjà été signalée dans de trés nombreux tissus. Quelques hypothèses sont présentées.
    Notizen: Summary During the transition between the fetal and postnatal periods associations between cell junctions and cell organelles appear in the liver of the mouse. These associations are of two types: desmosome-organelle and nexus-organelle. 1.Nexus-Organelles Association. Unilaterally or bilaterally, various organelles — mitochondria, cysternae, microbodies or lysosomes — adhere tightly along the gap. These associations appear only between the 21st day of gestation and the first postnatal day. Thereafter they gradually disappear and are replaced by desmosome-organelle associations. Another type of structure — ergastoplasmic saccules or cisternae of rough endoplasmic reticulum — become associated with the cell membrane. 2.Desmosome-Organelle Associations. In these complexes the desmosomal microfilaments are in close contact with membranes of the associated organelles — mitochondria or peroxysomes. The associations, which exist as early as the 13th day of gestation increase after the first postnatal day. The significance of these associations remains to be ascertained, especially since they occur in many other tissues. A few hypotheses are presented.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 149 (1974), S. 333-347 
    ISSN: 1432-0878
    Schlagwort(e): Neural lobe ; Mouse ; Growth and development ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Nerve fibres of the neurosecretory hypothalamo-hypophyseal tract were studied in embryonic C3H mouse neural lobes; at least four glands at each gestational day 15–19 were examined. Single axons and small bundles of fibres are visible at gestational days 15 and 16. By day 17 large fibre bundles penetrate between glial cells. They increase in number during the next two days. Electron-lucent and electron-dense vesicles are seen in the fibres of the 15th and 16th gestational days. In the 17–19 day-old embryos development is characterized by a successive rise in the number of the two types of vesicles. The mean diameter of the electron-lucent vesicles is approximately unchanged in all the stages examined (50 nm). The electron-dense vesicles increase in size from approximately 80–90 nm at days 15–16 to 140 nm at the 19th gestational day. By day 19 contacts between neurosecretory fibre terminals and the outer basement membrane of internal and peripheral capillaries are occasionally observed. The possibly adrenergic nature of a few terminals contacting peripheral vascular structures in 17 and 18 day-old embryos is suggested.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 36
    ISSN: 1432-0878
    Schlagwort(e): Ornithine decarboxylase ; Polyamines ; Mouse ; kidney ; Autoradiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ornithine decarboxylase, a key enzyme in polyamine biosynthesis and cell growth, has been localized in mouse kidney by autoradiography after administration of radiolabeled α-difluoromethylornithine. This drug is an enzyme-activated irreversible inhibitor of ornithine decarboxylase and forms a covalent bond with the enzyme. It was found that ornithine decarboxylase is present in all cell types studied but that the highest content occurs in the proximal convoluted tubules followed by the distal convoluted tubules and the collecting tubules. The majority of the enzyme is located in the cytoplasm but about 10–15% is present in the nuclei (often associated with nucleolus-like components) of the cells of the proximal and distal convoluted tubules. The labeled ornithine decarboxylase was lost rapidly from both nucleus and cytoplasm of all the cell types examined, and labeling by radioactive α-difluoromethylornithine was greatly reduced if the mice were pretreated for 5 h with cycloheximide to block protein synthesis. These results indicate that ornithine decarboxylase turns over rapidly in all of the cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 245-252 
    ISSN: 1432-0878
    Schlagwort(e): Pineal organ ; Interstitial cells ; Astrocytes ; Immunocytochemistry ; Rat ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Antigenic markers characteristic of astrocytes and their differentiative states (i.e., glial fibrillary acidic protein (GFAP), vimentin, and M1 and C1 antigens) were investigated in the pineal gland of mouse and rat using double immunolabeling techniques. In both species the socalled interstitial cells as characterized by TEM were shown to be astrocytes, since they expressed vimentin, but neither fibronectin (a marker for fibroblasts and endothelial cells) nor the neuron-specific L1 antigen or tetanus toxin receptors. Subpopulations of vimentin-positive pineal astrocytes were also GFAP- and C1- antigen-positive. M1- antigenpositive cells were not detected. It is concluded that a considerable proportion of interstitial cells in the pineal gland of rat and mouse are immature astrocytes which, in contrast to other parts of the central nervous system, persist into adulthood.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 473-478 
    ISSN: 1432-0878
    Schlagwort(e): Skin ; Oral mucosa ; Epithelial-mesenchymal ; interactions ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The interaction between adult stratified squamous epithelium and its supporting connective tissue possibly involves both permissive and directive influences. To examine the effect of vitality and specificity of connective tissue on the maintenance of epithelial structure and histo-differentiation, specimens of skin and oral mucosa from various regions of adult mice were separated using either EDTA or trypsin. Prior to transplantation, the epithelium was recombined with either inverted homologous connective tissue or with connective tissue that had been killed either by heating or repeated freeze-thawing. Epithelial sheets were also transplanted onto the graft bed alone or in combination with striated muscle or tendon. Normal patterns of cytodifferentiation were maintained when the epithelium was recombined with inverted or frozen-thawed subepithelial connective tissue but there was a loss of spatial organization on the frozen-thawed connective tissue. In contrast, heat-killed or trypsin-treated frozen-thawed subepithelial connective tissue and non-dermal connective tissue failed to maintain a viable epithelium. These observations suggest that subepithelial connective tissues (dermis, lamina propria) but not deep connective tissues facilitate epithelial proliferation and histodifferentiation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 209-212 
    ISSN: 1432-0878
    Schlagwort(e): Microprobe analysis ; Zinc ; Thymus ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Thymulin, a thymic hormone, is a nonapeptide requiring zinc for biological activity. It has been shown that epithelial cells, forming part of the thymic reticulum, secrete this hormone and/or store it within cytoplasmic vacuoles. X-ray electron-probe microanalysis (EPMA) has been used to detect zinc in the thymus. Low concentrations of zinc have been demonstrated in the dense granules contained in clear vacuoles of some epithelial cells in normal and ZnCl2-injected mouse thymuses, thus suggesting that the metal may be coupled to the peptide before the secretion of the hormone from the cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 211 (1980), S. 405-418 
    ISSN: 1432-0878
    Schlagwort(e): Intestine ; Mouse ; Cell isolation ; Enzymes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Suspensions of sequentially isolated villus and crypt cells were obtained in order to study certain biochemical changes associated with differentiation of epithelial cells in the small intestine of the mouse. Microscopic observation of the various cell fractions reveals that the epithelial cells detach as individual cells or small sheets of epithelium from the tip to the base of the villus, whereas cells in the crypt regions are separated as entire crypt units. The isolated cells retain their ultrastructural integrity as judged by electron microscopy. Chemical characterization of the various fractions shows that the total cellular protein content, expressed in activity per cell, remains relatively constant throughout the villus region followed by a noticeable drop in the crypt zone. On the other hand, sharp variations in values of cell DNA content are observed in the crypt zone depending on the reference of activity being used. Activity profiles of several brush border enzymes confirm the biochemical changes that occur during the migration of cells from the crypt to the villus tip, as observed in other species, with maximum activity of sucrase in the mid-villus region, of glucoamylase, trehalase, lactase and maltase in the upper third region, and of alkaline phosphatase at the villus tip. Forty-eight-hour suspension cultures of cell fractions corresponding to cells at the base of the villus and crypt zones show a moderate decrease in protein and enzyme activities to approximately 70% of their original value, with DNA content remaining stable throughout the incubation period. The use of biochemical activities as indicators of cellular integrity during cell culture is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 211 (1980), S. 441-448 
    ISSN: 1432-0878
    Schlagwort(e): Somatotroph ; Mammotroph ; Development ; Mouse ; Pituitary
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The pars distalis of the pituitary gland of the C57BL mouse was studied by means of electron microscopy during postnatal stages of males ranging in age from newborn through 24 days, with particular emphasis on the somatotrophs and mammotrophs. During this period, growth curves were plotted in order to correlate postnatal growth patterns with the state of differentiation of the somatotrophs in the pars distalis. In the newborn, the somatotrophs show well developed organelles, including rough endoplasmic reticulum and Golgi complexes. These cells are not as densely packed with granules as the adult somatotrophs; however, from days 5 through 24, they show a progressive accumulation of granules. Although mammotrophs are scarce in the newborn, they are readily distinguishable in the pars distalis at 5 days. Male mice in small litters show a progressive increase in body weight between birth and 11–12 days, at which time the rate slackens until 18–19 days when the rate again increases. Growth curves for mice from large litters are similar to those from smaller litters, except that the transitory decrease in rate is more prominent.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 236 (1984), S. 465-470 
    ISSN: 1432-0878
    Schlagwort(e): Tendon ; Collagen fibrils ; Morphometry ; Ultrastructure ; Loading ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This study was designed to gain more detailed morphological information on skeletal tendons in the course of adaptation to physical loading. The effect on collagen fibrils was investigated in 6-week-old mice by means of electron microscopy. Physical loading was performed on a treadmill 5 days a week for 1, 3, 5, 7 and 10 weeks. Morphometric analysis of collagen fibrils revealed the mean diameter, the diameter distribution, the number and the cross-sectional area. The principal observations included: 1. After one week of physical loading an increase in mean fibril diameter (30%, p≦0.01), in number (15%, p≦ 0.05), and in cross-sectional area (15%, p≦0.05), as well as a change in mean fibril diameter distribution. 2. From the third to the seventh week a fall under the level of the controls in mean diameter (26%, p≦0.01), in number (26%, p≦0.01), and a reduced cross-sectional area (17%, p≦0.01), accompanied by signs of splitting of individual collagen fibrils. 3. In the long-term study an increase in fibril number (29%, p≦0.01), a fall in mean diameter from 189 nm in the controls to 179 nm (p≦0.05) but no statistically significant change in the relative cross-sectional area (32%) per unit in comparison to unloaded tendons. The possible physiological implications of the findings are discussed in the light of several regulatory mechanisms known to appear during the course of physical loading in connective tissues.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 43
    ISSN: 1432-0878
    Schlagwort(e): (Na++K+)-ATPase ; Membrane markers ; Monoclonal antibody ; Ouabain ; Enzyme inhibition ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The antigen detected by the rat anti-mouse monoclonal antibody (m Ab), anti-BSP-3, has been initially described as a brain cell-surface protein. Evidence is presented that this m Ab recognizes mouse (Na++K+)-ATPase (ATP phosphohydrolase, E.C.3.6.1.3). The antigen, purified from mouse brain by means of affinity chromatography, migrated in SDS-polyacrylamide gels in the form of two polypeptide chains of 100000 and 48000 molecular weight, which could be shown to react with subunit-specific polyclonal antisera against ATPase in immunoblotting experiments. Purified BSP-3 antigen was bound to the specific (Na++K+)-ATPase inhibitor ouabain. Finally, the anti-BSP-3 m Ab was capable of immunoprecipitating the ATPase activity of a microsomal fraction from mouse kidney. The m Ab was used to study the localization of (Na++K+)-ATPase in different organs of the mouse. It stained the basolateral plasma membranes of polarized cells in immunofluorescence experiments, while the entire cell surface of unpolarized cells was labeled. Interestingly, several cell types did not react with the m Ab, indicating a possible heterogeneity of ATPases. Such a m Ab could prove to be a useful tool for studying localization, structure and function of (Na++K+)-ATPase.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 234 (1983), S. 713-722 
    ISSN: 1432-0878
    Schlagwort(e): Muscle ; Regeneration ; Precursor cells ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This paper tests the hypothesis that bone marrow stem cells can give rise to circulating muscle precursor cells. Irradiated host mice were reconstituted with bone marrow cells from a second strain of mice: the two strains were each homozygous for one of the two different isoenzyme forms of the enzyme glucose-6-phosphate isomerase, which enable cells of the two strains to be identified by different isoenzyme mobilities on starch gel electrophoresis. Isoenzyme patterns of 16 regenerated muscle isografts and 7 samples of host muscle (from 13 mice) were examined to determine whether donor bone marrow cells contributed to formation of new skeletal muscle. No evidence was found to support the hypothesis that myoblasts can arise from bone marrow precursor cells, although the possibility that muscle precursor cells derived from other tissues may circulate in the blood stream was not excluded.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 237 (1984), S. 337-342 
    ISSN: 1432-0878
    Schlagwort(e): Cauda epididymidis ; Velocity sedimentation ; Contraceptive ; Spermatogonia ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Androgenic steroids induce oligospermia at high doses, but few studies have assessed which cell types and spermatogenic processes are affected. Testis cell numbers and rate of differentiation were quantitatively evaluated in testosterone enanthate-treated male mice by use of histological and cell separation techniques. Reduction in the number of testicular germ cells in treated animals accounted for 40% of the total reduction of spermatozoa. Testis cells differentiated at a similar rate in treated and control animals. Spermatozoa moved to the cauda epididymidis a day earlier in testosterone-treated animals, and were lost from the cauda after only two days, rather than after the normal seven days. These results suggest that over half of the 98% reduction in sperm number in testosterone-treated animals occurred at the stage of passage through the cauda epididymidis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 61-68 
    ISSN: 1432-0878
    Schlagwort(e): Respiratory tract ; Trachea ; Bronchi, extrapulmonary ; Muscle, smooth ; Innervation ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the mouse, nerves were located throughout the trachea and extrapulmonary bronchi in both the smooth muscle and the connective tissue. However, no nerves were found within the epithelium. In the smooth muscle there were large numbers of nonmyelinated nerves. These were usually ‘en passant’ elements but varicosities containing small mitochondria and vesicles were also seen; these axons sometimes appeared to be efferent to the muscle. Unilateral cervical vagotomy reduced the numbers of nerves in the muscle of the trachea and ipsilateral primary bronchus, suggesting that they were afferent. The intramuscular nerves were characterized in terms of their complement of cytoplasmic organelles; in particular nerves containing many mitochondria disappeared following vagotomy. Pretreatment of mice with 5-hydroxydopamine to accentuate the electron-opacity of catecholamine-containing granules resulted in 3.5% of the nerves within tracheal muscle showing such granules. The afferent nerves of the smooth muscle may be complex branching structures with many varicosities. The absence of epithelial nerves may be related to the absence of the cough reflex in the mouse.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 238 (1984), S. 653-656 
    ISSN: 1432-0878
    Schlagwort(e): Tunicamycin ; Glycoprotein ; Intestinal epithelium ; Microvilli ; Freeze-fracture ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effect of tunicamycin, which is known to inhibit the synthesis of N-linked glycoprotein, on the duodenal absorptive epithelial cell of the mouse was studied in thin-section as well as freeze-fracture images. In tunicamycin-treated animals, the apical part of the epithelial cell was almost negative to the PAS reaction. Moreover, microvilli of the epithelial cell became shorter, larger in diameter, and fewer in number in tunicamycin-treated mice. In addition, freeze-fracture images revealed that the population density of membrane particles of the microvillus membrane was lowered by tunicamycin treatment. These results may indicate that the inhibition of synthesis of N-linked glycoprotein causes a decrease of membrane supply from the Golgi apparatus to the apical plasma membrane.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 208 (1980), S. 165-168 
    ISSN: 1432-0878
    Schlagwort(e): Cardiac muscle cells ; Trabeculae carneae ; Fibrillar pattern ; Mouse ; Rat ; Rabbit
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The cardiac muscle fibers in the trabeculae carneae of mice, rats, and rabbits show a special arrangement of densely interwoven myofibrils. They cross at various angles; however, a preferred orientation of the fibrils cannot be discerned. It is suggested that due to this arrangement the myocytes of trabeculae are not able to contract to the same extent as ventricular myocytes, but thereby gain a high rigidity during contraction. Hence, they may play a principal role as “guiding ridges” for the flow of blood, thereby improving hemodynamics.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    Parasitology research 62 (1980), S. 47-61 
    ISSN: 1432-1955
    Schlagwort(e): Flagellates ; Spironucleus ; Mouse ; Ultrastructure ; Systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Using light and electron microscopy, we studied the ultrastructure ofSpironucleus muris (syn.Hexamita muris) from spontaneously and experimentally infected normal and athymic mice. Kinetosomes and cytoskeletal fibers arranged in two-fold rotational symmetry are similar to the speciesSpironucleus elegans from amphibians. Taxonomic proposals and a possible evolutionary scheme for diplomonad genera accepted at the last International Congress of Parasitology are given. The genusHexamita should be divided into two new genera:Hexamita (usually free-living) andSpironucleus (exclusively parasitic). We consider previous descriptions of hexamitiasis in rodents as dealing with spironucleosis. We distinguish a fresh and an old cyst of the parasite on the basis of structure, light refraction, location in the host, and infectivity. The transition from a fresh to an old cyst paralles the dessication of feces. The trophozoites can damage the microvilli and penetrate into the epithelium. We explain the differences in findings concerning intestinal lesions and forms of the disease (from acute to chronic to latent) by differences in the virulence of different parasite strains and by differences in inherent host resistance.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 233 (1983), S. 227-231 
    ISSN: 1432-0878
    Schlagwort(e): Muscle-tendon junction ; Ultrastructure ; Myofibrillar pattern ; M. flexor digitorum longus ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The muscle-tendon junctions of adult mice show a special arrangement of myofibrils. Essentially, the myofibrils are oriented in an anchor-like manner in the large finger-shaped processes of the muscle fiber, which contain “mitochondrial sacks” (Demmel et al. 1979) in a subsarcolemmal position. Furthermore, the single myofibril frequently branches out into smaller fibrils. It is suggested that due to the three-dimensional arrangement, these processes gain a high rigidity during contraction, thus maintaining their shape and preserving the “mitochondrial sacks”.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 51
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 205 (1980), S. 411-421 
    ISSN: 1432-0878
    Schlagwort(e): Synapse formation ; Neuroblastoma cells ; Time course ; Monolayer cultures ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Neuroblastoma cells grown on substrates in culture develop long processes and assume the morphology of normal neurons as judged light microscopically. The development of synapses in the cultured tissue is studied by periodic electron microscopic examination of the areas of contact between cells. The initial expiants are free of any apparent synaptic contacts. After 48 h in culture, simple swellings or boutons are detected at the periphery of the cells or at the end of the fine processes. These initial synaptic profiles contain a few vesicles but lack mitochondria. The synaptic vesicles appear to originate from the smooth endoplasmic reticulum. Further expiants remain primitive, only the number of vesicles in the cytoplasmic swellings or boutons increases. These clusters of vesicles are 40–60 nm in diameter and morphologically distinguishable from the synaptic vesicles of normal neurons. There are no postsynaptic folds or membrane thickenings. Specialized cell contacts between cells are also present.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 206 (1980), S. 65-72 
    ISSN: 1432-0878
    Schlagwort(e): Submandibular gland ; Mouse ; Freeze fracture ; Myoepithelial cells ; Gap junction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the submandibular gland of the male mouse, myoepithelial cells are found not only located to the endpieces and intercalated ducts, but also around the striated (or granulated) ducts. Irrespective of their location in the gland, the myoepithelial cells and their processes were found to be connected by gap junctions. It is suggested that these gap junctions play a key role in the synchronization of the contractile function of the myoepithelial cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 53
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 206 (1980), S. 115-122 
    ISSN: 1432-0878
    Schlagwort(e): Explant cultures ; Synaptic morphology ; Magnesium-rich medium ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present study examines the ultrastructure of synaptic profiles developed in explant cultures of immature mouse cerebral cortex, maintained for prolonged periods in a magnesium-rich environment. The ethanolic phosphotungstic acid method was employed in addition to conventional preparation procedures so that paramembranous densities could be clearly observed. Although presynaptic terminals were frequently packed to capacity with vesicles in cultures maintained in magnesium-rich media, there was always a proportion which contained loosely collected vesicles. Few other changes in synaptic morphology were apparent and the paramembranous densities were unaffected. The reasons for the effectiveness of the transmission block, the absence of any change in the morphology of paramembranous densities, and the excessive crowding of presynaptic vesicles are considered and discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 54
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 208 (1980), S. 247-252 
    ISSN: 1432-0878
    Schlagwort(e): Pineal gland ; Cold ; Ultrastructure ; β-receptor ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Quantitative electron microscopic studies on the mouse pineal gland were done to elucidate the mechanism of the response of the granulated vesicles in pinealocytes to acute cold exposure. An increase in the number of the granulated vesicles in the mouse pinealocytes occurs following administration of isoproterenol and this increase is prevented by pretreatment with the βadrenergic blocking agent, propranolol. In addition, a numerical increase of the granulated vesicles in response to acute cold exposure is abolished in mice pretreated with propranolol or in adrenalectomized animals. The results suggest that catecholamines released from the adrenal medulla, but not from sympathetic nerve endings, may cause the response of the granulated vesicles to cold by way of β-receptors.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 55
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 212 (1980), S. 497-508 
    ISSN: 1432-0878
    Schlagwort(e): Lymphocyte migration ; X-irradiation ; Autoradiography ; Spleen ; Lymph node ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The migration of radiolabeled intravenously injected B lymphocytes through thymus-dependent areas was studied in lymphoid organs of mice with experimentally defined T cell domains (B cell-deprived mice or “T” mice). In the spleen, B cells were found to enter the peri-arteriolar lymphoid sheath (PALS) by two routes: (i) via the marginal zone, and (ii) via reticulin sheaths surrounding terminal arterioles. B cells migrated through the peripheral and central PALS and initiated the formation of primary follicles in the peripheral PALS 6 h after injection. Distinct primary follicles were noted at 18 h after injection of the labeled B cells. After 24 h small numbers of labeled cells were also noted in the efferent lymphatic vessels of the spleen. The reconstitution of B cell compartments in the mesenteric lymph node was delayed compared to the spleen. B cells entered the nodal stroma across the wall of high endothelial venules in the paracortex and by 6 h were found scattered throughout the paracortex. Isolated clusters of a few labeled cells were noted in the outer cortex at 18 h after cell transfer. Defined primary nodules were seen only 24 h after reconstitution. A minority of labeled cells was found at 24 h in the cortico-medullary junctions and in medullary cords. The present study shows that B lymphocytes traverse T cell domains on their way to their own specific B cell compartments. The immunological significance of this particular migration route is discussed in view of data on the cellular cooperation of B cells, T cells and macrophages during the humoral immune response.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 56
    ISSN: 1432-0878
    Schlagwort(e): Pineal gland ; Serotonin ; Cytochemistry ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the pineal gland of the mouse the distribution of serotonin (5-HT) and its eventual relationships to a protein secretion were examined by means of fluorescence histochemical (Falck-Hillarp) and ultracytochemical (chromaffin and argentaffin) methods. (1) Yellow formaldehyde-induced fluorophores, characteristic of high concentrations of 5-HT, were found in pinealocytes, interstitial cells and sympathetic adrenergic nerve endings. The 5-HT content was studied according to the circadian variations and different drug treatments. (2) By use of ultracytochemical methods in untreated control mice precipitates indicative of 5-HT were found over dense-core vesicles (DCV; mean diameter: 100 nm) of the pinealocytes and the vesicular compartment of the sympathetic nerve fibers. After reserpine and p-CPA treatments, the reactivity of the DCV disappeared, but the protein secretion accumulated within the DCV was still present. After nialamide treatment the precipitates in the DCV increased and, similar to control mice, masked the protein secretion. Taking into account the specificity and sensitivity of these three complementary methods, previous biochemical data in mammals and ultracytochemical data in submammalian vertebrates, synthesis, storage, catabolism and release of 5-HT in the mouse and hamster pineals are discussed at the cellular level. Different pools of 5-HT are present: agranular and granular in pinealocytes and sympathetic nerve endings; agranular in interstitial cells. In the mouse, only a small portion of the total 5-HT content appears to be secondarily taken up by the DCV. Within the DCV, 5-HT is possibly bound to a protein secretion of unknown significance (peptidergic neurohormone?). In the pinealocytes, which are sensitive to a large variety of inputs, processes of indole and protein secretion are found. These cells apparently are the recepto-secretory elements of the mammalian pineal gland. They can thus be classified as a member of the diffuse neuroendocrine system of the paraneuron group.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 218 (1981), S. 117-121 
    ISSN: 1432-0878
    Schlagwort(e): Synovial membrane ; B-cells ; Intimal interstitium ; Long-spacing-collagen ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An ultrastructural study of the synovial membrane in mice revealed that, in addition to specific polypeptide-producing secretory cells (B-cells), the intima is characterized by a specific differentiation of the interstitium adjacent to the synovial cavity. Scattered collagen fibrils are embedded in a fine fibrillar material, which often appears as cross-striated strands resembling long-spacing-collagen (periodicity from 90 to 120nm). Similar material was found along the synovial cavity in the rat, guinea pig, rabbit and man. The close relationship between this material and B-cells observed in the mouse suggests that the maintenance of the specialized intimal interstitium may depend on the secretory function of B-cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 58
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 218 (1981), S. 123-128 
    ISSN: 1432-0878
    Schlagwort(e): Synovial membrane ; B-cells ; Specific secretory activity ; Endocrine influence ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the mouse, hypophysectomy and treatment with propylthiouracyl provoke structural alterations in the B-cells of the synovial membrane. These changes are interpreted as secretory stimulation of the B-cells, which are intimal polypeptide-producing secretory elements specific to the synovial membrane. A direct hormonal influence on the B-cells cannot be excluded; however, chemical changes in the extracellular medium, due to hormonal deficiencies, are more probably involved in the stimulation of these cells, the main function of which seems to be the maintenance of the specialized structure of the intimal interstitium.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
    ISSN: 1432-0878
    Schlagwort(e): Substance P ; Immunocytochemistry ; Neurohypophysis ; Hypothalamus ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Substance-P immunoreactivity has been located in semithin sections of mouse hypothalami and pituitaries and compared with the distribution of other hypothalamic peptides. In the mouse, nerve fibres and terminals reacting with antibodies against substance P (SP) were detected both in the external zone of the median eminence (ME) and in the neural lobe of the pituitary. Immunoreactive SP (ISP) axons of the ME did not react with antibodies against other peptides, i.e. arginine-vasopressin (AVP), oxytocin (OT), somatostatin and enkephalin, and were also negative with an antibody to serotonin. In the neural lobe, SP immunostaining occurred in AVP but not in OT axons. In the hypothalamus, ISP axons were widespread but conspicuously lacking in areas containing AVP neurones, i. e. in the suprachiasmatic nucleus and the clusters of AVP cells in the SO and PV nuclei. In contrast, multiple ISP endings were seen in contact with OT neurones. Immunoreactive cell bodies, only detected after colchicine treatment, belonged to two distinct classes of neurones: 1) single AVP neurones of the SO and PV nuclei; 2) specific (staining only for SP) neurones, scattered or grouped in different areas of the hypothalamus, not showing relationship with any circumscribed nucleus. These results reinforce the opinion that SP can be released as a neurohormone into the vascular portal system and can directly affect the pars distalis. The presence of immunoreactive SP in the neural lobe, which has not been reported in species other than the mouse, may have a different physiological significance.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 224 (1982), S. 189-194 
    ISSN: 1432-0878
    Schlagwort(e): Glia ; Horseradish peroxidase ; Brain development ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The transport of horseradish peroxidase (HRP) applied to exposed pial surfaces of the brain was studied in newborn, 4-, 7- and 12-day-old, and adult mice. In the telencephalon the cell bodies of radial glia were found to accumulate the tracer. Labeled cells occurred in the subventricular zone of the lateral ventricle during the first postnatal week; they became gradually restricted to an area around the stria terminalis (ventrolateral ventricular corner) by day 12. At later stages no HRP transport could be traced from the surface of the telencephalon. In the cerebellum, HRP was transported from the surface to the cell bodies of Bergmann glia in all age groups studied including adult animals. It is concluded that radial glia and their derivatives share the capacity of transporting material between various cerebrospinal fluid compartments.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 230 (1983), S. 661-670 
    ISSN: 1432-0878
    Schlagwort(e): Preimplantation embryos ; Mouse ; Ultrastructure ; Morphometric analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary During cleavage, both qualitative and quantitative morphologic characters of mouse ova change. Up to the 8-cell stage, the volume density of mitochondria remains nearly the same although it increases during early and late blastocyst stages. While a rise of the volume fraction of granular endoplasmic reticulum is noticed during cleavage, the volume density of agranular endoplasmic reticulum diminishes gradually from the 1-cell stage onwards. An increase in the volume fraction of autophagic vacuoles is found, the maximum being reached in early blastocysts. The volume fraction of crystalloid inclusions slightly increases after the 4-cell stage, but this increase is statistically insignificant. The volume density of filamentous material (plaques) conspicuously decreases in all studied embryos from the beginning of cleavage. Starting with the 2-cell stage, the volume fraction of lipid droplets remains practically unchanged. No differences in volume densities of the Golgi apparatus, multivesicular and residual bodies, and large cytoplasmic vesicles with medium electron-dense content are found between the respective cleavage stages.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 231 (1983), S. 135-142 
    ISSN: 1432-0878
    Schlagwort(e): Antibody formation ; Spleen ; Horseradish peroxidase ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Specific antibody formation in the spleen was described in mice primed subcutaneously with horseradish peroxidase (HRP) and boosted intravenously with the same antigen. The first specific antibody-forming cells responding to the booster injection were observed after one day in the periarteriolar lymphocyte sheath (PALS). The number and staining intensity of these cells greatly increased subsequently. Between day 3 and 6 after the booster injection a shift was observed in the distribution of antibody-forming cells from the PALS to both the site of entry of the central artery in the PALS and the site where the blood passes via terminal arterioles to the red pulp. Specific antibody-forming cells became highly concentrated in these areas, which constitute the so-called marginal zone bridging channels. After day 6 the number of antibody-forming cells decreased sharply. On the basis of this distribution pattern it was suggested that after subcutaneous priming and intravenous boosting specific antibody-forming cells migrate from the popliteal lymph nodes to the spleen and gradually leave the spleen at later stages of the response. Specific antibody-forming cells did not occur in the germinal centers during any stage of the response.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 213 (1980), S. 475-482 
    ISSN: 1432-0878
    Schlagwort(e): Vaginal epithelium ; Prenatal estrogen treatment ; Mucification ; Ultrastructure ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary After transplacental treatment of mice with estrogens, a heavy mucification was found in the fornices of the vaginae of the offsping. The resulting mucified stratified epithelium is described by light and electron microscopy. It consists of two different cell types: cells forming mucus on top of cells forming tonofilaments. Mucus formation is usually attributed to treatment with progestagens, or with with estrogens combined with vitamin A. Estrogen treatment per se has been shown to be responsible for tonofilament formation. Our unexpected findings are discussed against the background of different theories of development of vaginal epithelium as well as their possible interpretation as beginning of adenosis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 217 (1981), S. 647-659 
    ISSN: 1432-0878
    Schlagwort(e): Cell culture ; Neuro-muscular junctions ; Short-term preparations ; Mouse ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The development of neuro-muscular junctions (mouse, rat) from the time of first contact between neurons and myotubes in culture and the changes which lead to the formation of functional synaptic contacts have been investigated using light microscopy and ultrastructural techniques. An extensive basal lamina was present when the neuronal cell population was added to the developing myotubes in culture. The nerve cells were initially strongly attracted to each other and nerve cell aggregates formed rapidly. It was only when nerve fibres began to grow out of these aggregates to contact developing myotubes that changes within the cytoplasm of the two adjacent cells were observed. These developments included accumulations of filaments, membrane densities, mitochondria and large clear vesicles within both cells in the region of contact. In addition, collections of glycogen granules and an extensive membrane reticular complex were found within myotubes, and an extensive granular material filled many of the nerve processes. The basal lamina within the intercellular space appeared more electron-dense than elsewhere and was traversed by strands linking the two cell membranes. These features all appeared to be stages in the initial formation of neuro-muscular junctions. It was only after these events had occurred that presynaptic vesicles gradually appeared within the future nerve terminal. The results of this paper therefore support the view that synaptic transmission at developing mammalian neuromuscular junctions is not necessarily dependent on the presence of presynaptic vesicles.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 65
    ISSN: 1432-0878
    Schlagwort(e): Sciatic nerve ; Endoneurial sheath ; Collagen ; Injuries ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The endoneurial collagen sheath around teased nerve fibres following crush injury was studied by scanning electron microscopy and compared with uninjured sciatic nerve fibres and with fibres from the dystonic mutant mouse. Following crush injury the endoneurial collagen became more abundant than seen in untreated nerve fibres and formed large, separate and longitudinally oriented bundles. However, by four weeks post injury the sheath regained a normal external appearance. Mutant nerve fibres were also associated with more than the usual amount of collagen, but the sheaths were more disorganised, with a marked disorientation and irregular aggregation of collagen, and these abnormalities were not confined to obviously degenerating or demyelinated regions of the fibres. The dystonic abnormalities of the endoneurial sheath may be important in the mechanism of the neuropathy.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 221 (1981), S. 77-83 
    ISSN: 1432-0878
    Schlagwort(e): Nerve growth factor ; Mouse ; Submandibular gland ; Immunohistochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Nerve growth factor (NGF) was localized in the mouse submandibular gland by means of indirect immunofluorescence applied to 0.5 μmthick sections of freeze-dried, plastic-embedded tissue. The antibody to NGF (IgG-fraction) was raised in rabbits immunized with pure 2.5 S NGF from submandibular glands of adult male mice. In the male gland anti-NGF bound selectively to the secretory granules was present in the cells of the granular ducts. Immunoreactive granules extended from the perinuclear region toward the apical pole. In the female gland immunoreactive cells and granules were considerably less abundant than in males. Immunofluorescence was confined to individual secretory cells located in the wall of the granular striated duct. In the present study no support was found for the hypothesis suggesting that immunoreactive NGF is formed within the secretory granules during their transport from the perinuclear region to the apical pole.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 221 (1981), S. 169-180 
    ISSN: 1432-0878
    Schlagwort(e): Spermiogenesis ; Mouse ; Male sterility ; p s p s/hpy hpy ; Geneinteraction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In male mice homozygous for both p s and hpy, two recessive, pleiotrophic, mutations, gametogenesis is normal through meiosis but no functional spermatozoa are produced. Spermiogenesis is abnormal from the Golgi phase on. The types of abnormalities seen during the early and mid-stages of Spermiogenesis are characteristic of those associated with the presence of the p s mutation whereas those associated with the hpy mutation appear during the later stages of spermatid development. While centriolar ultrastructure was normal, axonemal structures were only rarely encountered and no late spermatids with recognizable flagella were seen. Some late spermatids showed head abnormalities of the type characteristic of the ps mutation while others were recognizable as being of the hpy type. A released “gamete” usually consisted of a distorted nucleus and associated acrosome enclosed in a tightly fitting plasma membrane. No spermatids exhibiting a novel phenotype were encountered. The findings support the view that, despite their simultaneous presence in the double homozygote, each mutation acts autonomously. These studies also allow a similar inference to be made with respect to the extent of the interrelationship of the other major sub-processes of Spermiogenesis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 223 (1982), S. 187-200 
    ISSN: 1432-0878
    Schlagwort(e): Tight junctions ; Gap junctions ; Colchicine ; Microtubules ; Liver (hepatocytes) ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Following the administration of colchicine at a dosage (1 mg/mouse) known to cause an antimicrotubular effect, membranes as well as tight and gap junctions of hepatocytes were studied using the thin-sectioning and freeze-fracturing technique. As early as l h after administration of colchicine the intercellular spaces were dilated and vacuoles were visible within the cytoplasm. The bile canaliculi became enlarged, and after lanthanum perfusion the tracer was found in the canalicular lumen, i.e., the tight junctions became permeable to the tracer. These findings correlated with a disorganized arrangement of the tight junctional strands of the zonula occludens. In some regions the strands showed interruptions and frequently ended freely in a diffuse pattern on the plasma membrane. Proliferation of tight junctions could be observed at various locations on the plasma membrane. The gap junctions also exhibited alterations. They showed an irregular outline with outpouchings, in addition to an enlargement in their total area from approximately 0.5 μm2 in controls up to approximately 2 μm2 in treated mice. The surface area occupied by these junctions increased from 4 % (controls) to 20% (treated) of the hepatic plasma membrane. In the cytoplasm of hepatocytes from colchicine-treated mice gap-junctional vesicles were frequently observed. In view of the antimicrotubular effect of colchicine it is tentatively suggested that the intact microtubular system of the cell may play a decisive role in the regular formation of gap and tight junctions, either directly or indirectly via microfilaments.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 219 (1981), S. 209-211 
    ISSN: 1432-0878
    Schlagwort(e): Herring bodies ; Median eminence ; Myelinated axons ; Mouse ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The posterior part of the median eminence of the albino mouse (CF # 1-JCL) contains a cluster of myelinated axons beneath the tanycyte layer. Among them, small Herring bodies surrounded by myelin sheaths are revealed by electron microscopy. These structures contain electron-dense bodies, lamellar bodies, autophagic bodies, autophagic vacuoles, and neurofilaments. A few neurosecretory granules and mitochondria are also present. Some myelinated axons contain mostly accumulated neurosecretory granules.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 219 (1981), S. 217-220 
    ISSN: 1432-0878
    Schlagwort(e): Ependymal cells ; Cilia ; Ciliary necklace ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In ependymal cells of the mouse the neck region of all cilia examined by means of transmission electron microscopy exhibited rows of electron-dense spines. These structures correspond to the ciliary necklace reported from freeze-etch studies, a structure presumed to serve as an energy-regulating system in motile cilia.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 220 (1981), S. 61-72 
    ISSN: 1432-0878
    Schlagwort(e): Spinal cord ; Ependyma ; Meninges ; Light-and electron-microscopy ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In addition to ependymal epithelial cells, numerous tanycytes are found along the entire central canal of the mouse. These tanycytes are arranged in clusters in the cervical, thoracic and lumbar segments of the spinal cord. In the conus medullaris, tanycytes separate and ensheath bundles of myelinated and unmyelinated axons; their processes take part in the formation of the stratum marginale gliae. In the caudal part of the spinal cord, the ventral wall of the central canal is thin and some areas are reduced to a single-cell thickness. In this region, ependymal cells participate directly in the formation of the stratum marginale gliae. The meninges consist of the intima piae, the pia mater, the arachnoid, a subdural neurothelium and the dura mater. The subarachnoid space appears occluded and opens only around the spinal roots. In the vicinity of the spinal ganglia, the dura mater, the subdural neurothelium and the arachnoid form a cellular reticulum.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 229 (1983), S. 183-189 
    ISSN: 1432-0878
    Schlagwort(e): Hypothalamus ; Arcuate nucleus ; Testosterone ; Karyometry ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of testosterone administration on the hypothalamic arcuate nucleus were studied in adult male mice by means of karyometry. Four animals per group were sacrificed 1, 2, and 3 h after intramuscular injection of 100 μg testosterone propionate/100 g body weight. The nuclear diameter of neurons was measured in serial coronal sections. Testosterone induced an increase in the nuclear diameter of neurons located in the dorsal and medial periventricular zones of the arcuate nucleus. The neurons exhibiting the greatest changes in nuclear diameter were situated in the rostral portion of the nuclear area examined. In the central portion of the arcuate nucleus no response to testosterone was found. The present data support previous observations showing mosaically arranged nerve-cell groups in this hypothalamic nucleus.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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