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  • 11
    ISSN: 1432-2013
    Keywords: Two-Kidney-Goldblatt Hypertension ; Renin Containing Granules ; Epitheloid Cells of Afferent Arterioles ; Morphology of Formation of Secretory Granules ; Hyporeninemia ; Renal Cortical Renin ; Plasma Renin Activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Renal cortical and plasma renin activities and the electron microscopic appearance of juxtaglomerular epitheloid cells were investigated in the unclamped renin-depleted kidney of rats with two-kidney-Goldblatt hypertension after removal of the clamped kidney. Within 24 h the renal renin content fell to still lower values, on the 2d day, it rose to one half its normal value, on the 7th day it reached its control value. Renin activity of plasma did not significantly differ from zero until the 3d day after removing the clamped kidney, reached 20% of normal on the 7th day and normal values between the 7th and the 21 st day. Sparse secretory granules appeared in the remaining renal cortex 12 h after removal of the clamped kidney. After 24 h secretory granules were formed by confluence of Golgi vesicles. After 2 days cisternae appeared in the rough-surfaced endoplasmic reticulum. After 4 days the electron-microscopic picture became normal. Renin appears to be elaborated in the rough-surfaced endoplasmic reticulum and concentrated into granules by the Golgi-apparatus. A fraction of the renal renin does not appear to be available for secretion.
    Type of Medium: Electronic Resource
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  • 12
    ISSN: 1432-0738
    Keywords: Methyl mercury ; Toxicokinetics ; Differential toxicity ; Japanese quail ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Distribution of a single oral dose of methyl mercury (10 mg Hg/kg body weight) was followed from 90 min up to 120 h in plasma, erythrocytes, and brain of Japanese quails and rats. Significantly higher Hg concentrations were observed in plasma and brain of quails and red blood cells of rats. Blood/brain ratio decreased in quails from 6 to 2 at 24 h and 120 h respectively, whereas it increased in rats. Erythrocyte/plasma ratio in quails was about three times lower and averaged 54. The differences in Hg distribution were accompanied by a more than 3-fold higher acute toxicity in quails under adequate experimental conditions.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Infection 11 (1983), S. 33-34 
    ISSN: 1439-0973
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Cefotaxim-Konzentration in Prostata-Adenom-Gewebe nach Injektion von 2 g i.v. wurde gemessen. Bei den Bestimmungen wurde der Blutgehalt in den Gewebeproben berücksichtigt. Die Unterschiede zwischen den vorliegenden Ergebnissen und solchen, die von anderen Gruppen publiziert wurden, werden diskutiert.
    Notes: Summary Cefotaxime concentrations were determined in samples of prostatic adenomas following a 2 g i.v. injection. The level of blood contamination in the samples was taken into consideration when determinations were made. Differences between our results and those published by other groups are discussed.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 94 (1969), S. 220-231 
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Funktion des rauhwandigen endoplasmatischen Retikulums (ER) und des Golgi-Apparates nach einer Fütterung von HeLa-Zellen in der Kultur läßt sich in einigen Punkten mit den Aufgaben dieser Systeme bei der Sekretbildung in der Pankreaszelle vergleichen. Das Endprodukt, die Cytosomen, entspricht dann den Enzymgranula. Ihr Inhalt wird aber nicht frei, sondern der Digestion durch eindringende zelleigene Fermente überlassen. Mikropinocytose-Vesikel haben als Material das Nährmedium hereingebracht. Die Golgi-Vakuolen stellten mit ihrer Membran das Behältnis und die dem ER entsprossenen und in die Golgi-Vakuolen ebenfalls einwandernden Golgi-Vesikel die Fermente. Die vesikuläre Struktur der Cytosomen stammt also von den Mikropinocytose- und Golgi-Vesikeln. Zur Stützung dieser Hypothese werden elektronenmikroskopische Bilder demonstriert, die die verschiedenen Zustände des Golgi-Apparates bei HeLa-Zellen zeigen, je nachdem sie ungefüttert oder 60 bzw. 30 min nach einer Fütterung fixiert worden sind. Beim Mediumwechsel z.T. zugesetztes Ferritin ließ erkennen, ob die in dem Golgi-Apparat und den Vakuolen liegenden Vesikel aus dem ER-System oder der Mikropinocytose stammten.
    Notes: Summary The activity of the rough-surfaced endoplasmic reticulum (ER) and Golgi apparatus in HeLa-cells following feeding is partly comparable to the function of these systems in pancreatic acinar cells during secretory activity. The final product, the cytosomes, corresponds to the secretory granules except that they, rather than having their contents emptied from the cell, are digested by endogenous enzymes. The substrate of the cytosomes is introduced by the micropinocytic vesicles containing the nutrient medium. The membranebound receptacles are the Golgi vacuoles, while the Golgi vesicles containing the enzymes and originating in the ER migrate into these Golgi vacuoles. The vesicular structure of the cytosomes is thus based on their content of micropinocytic and Golgi vesicles. In favour of this hypothesis, electron micrographs of the HeLa-cells demonstrate the different stages of the Golgi apparatus according as to whether the cells are fixed in an unfed condition or 30 or 60 min after the feedings. Ferritin added in part to the new medium enables us to distinguish whether the vesicles lying in the Golgi apparatus and in the vacuoles originate from the ER-system or from the micropinocytic vesicles.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 92 (1968), S. 360-366 
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Während der periodischen lichtmikroskopischen Pinocytoseruhe in einer Zellkultur von HeLa-Zellen und isolierten Herzmuskelzellen besteht noch eine ausgeprägte Micropinocytose. Es wird angenommen, daß die Mikropinocytosebläschen einige Zeit nach der Fütterung der Kulturen schon vorfermentiertes Medium enthalten, das die Zelle, ohne daß erst Lewissche Pinocytosevakuolen daraus entstehen müssen, verdauen kann.
    Notes: Summary During the periodical rest of the lightmicroscopical pinocytosis in a culture of HeLa-cells and isolated heart muscle cells a pronounced micropinocytosis subsists. It is supposed that a few days after feeding the cultures the micropinocytotic vesicles contain prefermented medium, which the cells are able to digest, before Lewis' pinocytotic vacuoles are formed.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 79 (1967), S. 244-258 
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Der Beweis für das Vorkommen von Sekretgranula in den epitheloiden Zellen des Meerschweinchens ist bisher von keinem Autor erbracht worden. Ihre Abwesenheit ist um so erstaunlicher, als die Renin-Aktivität in der Niere dieses Tieres etwa 1/10 der der Ratte mit ihren stark granulierten Epitheloidzellen beträgt und die des Menschen sogar übertrifft. In unserem Untersuchungsgut finden wir hin und wieder einige wenige, wahrscheinlich Renin enthaltende Granula (Abb. 1–4). Anscheinend erfolgen Synthese und Ausscheidung des Enzyms im gleichen Rhythmus; zu einer geringgradigen Speicherung kommt es offenbar nur unter bestimmten funktionellen Bedingungen. Die Goormaghtighschen Zellen (Abb. 5) zeigen kein besonderes auffälliges artspezifisches Verhalten. An der Macula densa wird erstmals eine starke Erweiterung sowohl der intracytoplasmatischen Einfaltungen des basalen Plasmalemms — des „basalen Labyrinthes“ — als auch der Interzellularspalten beschrieben (Abb. 6–9). Diese oberhalb der Basalmembran gelegenen „Pseudovakuolen“ sind somit extrazellulär und möglicherweise als morphologisches Äquivalent einer starken Reabsorptionstätigkeit zu deuten. Es ist zur Zeit noch nicht entschieden, ob sie mit der von uns angewandten Präparationstechnik auch bei anderen Tieren und beim Menschen darstellbar sind.
    Notes: Summary The presence of secretory granules in the epithelioid (juxtaglomerular) cells in the media of the preglomerular portion of the afferent arterioles in the kidney of the Guinea pig has not been proven by any author until now. The absence of these granules is all the more astonishing in view of the fact that the renin activity of this animal is about 1/10 of that of the rat — with its highly granulated cells — and even surpasses that of humans. In our inbread strain rare granules likely containing renin can be found from time to time (Fig. 1–4). Apparently, the synthesis and extrusion of the enzyme takes place with the same rhythm; a very low degree of accumulation occurs probably only under certain functional conditions. The Goormaghtigh Cells (Fig. 5) show no noticeable differences specific for the Guinea pig. In the Macula densa highly developed enlargements of the basal infoldings of the plasma membrane — “basal labyrinthe” — as well as of the intercellular spaces are described for the first time (Fig. 6–9). These enlargements (“Pseudovacuoles”), situated above the basement membrane, are extracellular and can possibly be interpreted as the morphological equivalent of a high degree of absorption activity. At the present time it has not been decided, if, using the authors' technique, these enlargements can be demonstrated in other animals and humans.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 79 (1967), S. 364-373 
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Arbeit befaßt sich mit dem elektronenmikroskopischen Verhalten der sogenannten endoepithelialen Kapillaren. Als Untersuchungsgut dienten normaktive Rattenschilddrüsen. Indem die Kapillaren in den Epithelsaum der Follikel eindringen, schieben sie dessen ununterbrochene Basalmembran gewissermaßen vor sich her. Drüsenzellen und Endothelzellen sind somit durch eine subepitheliale Basalmembran, einen perikapillären Spaltraum mit kollagenen Fibrillen und eine ebenfalls lückenlose subendotheliale Basalmembran voneinander getrennt. Der Zellkern der Endothelzellen liegt in den meisten Fällen auf der vom Follikelepithel abgewandten Seite. In dem epithelnahen Bereich ist das Endothel jedoch größtenteils außerordentlich dünn und fenestriert. Diese gesetzmäßige Querschnittstruktur begünstigt den gegenseitigen Stoffaustausch zwischen Blut und endokrinen Drüsenzellen.
    Notes: Summary Electron microscopic observations were made on the so-called endoepithelial capillaries of the normally active thyroid of Wistar rats. When the capillaries advance in the epithelial layer, they cause an infolding of its uninterrupted basement membrane. As a result, glandular cells and endothelial cells are always separated by a subepithelial basement membrane, a pericapillary space containing collagen fibrils, and a subendothelial basement membrane which also is uninterrupted. In most cases, another typical feature is observed: The endothelial nuclei lie on the remote side of the follicle epithelium, while an exceedingly thin and fenestrated endothelium occupies the neighboring side. This characteristic configuration of the wall of the endoepithelial capillaries favors the reciprocal exchanges between the blood and the endocrine gland cells.
    Type of Medium: Electronic Resource
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