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  • Spektralphotometrie  (167)
  • Rat  (115)
  • Springer  (282)
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
  • Wien : Geolog. Bundesanst.
  • 2010-2014
  • 2005-2009
  • 1975-1979  (282)
  • 1940-1944
Collection
Publisher
  • Springer  (282)
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
  • Wien : Geolog. Bundesanst.
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Year
  • 1
    Electronic Resource
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    Springer
    Calcified tissue international 27 (1979), S. 161-164 
    ISSN: 1432-0827
    Keywords: Osteoporosis ; Ovary ; Rat ; Vitamin D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Fifty adult female rats were used to study the effect of 1-alpha-hydroxyvitamin D3 (1α-OH-D3)on bone after oophorectomy. The experimental period was 6 months. At the end of the experiment the femurs and the tibias were investigated for bone mass and composition. Significant signs of osteopenia occurred as a result of oophorectomy. The treatment with 1α-OH-D3 induced only minor changes in blood chemistry but increased bone mass significantly. The findings support the view that 1α-OH-D3 may be a valuable tool in the treatment of osteoporosis resulting from ovarian insufficiency.
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  • 2
    ISSN: 1432-0878
    Keywords: Catecholamine synthesizing enzymes ; Adrenal medulla ; Embryonic induction ; Adrenocortical hormones ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cellular localization of the enzymes tyrosine hydroxylase (TH), aromatic amino-acid decarboxylase (or dopa decarboxylase, DDC), dopamine β-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT) in the adrenal medulla of adult rats and rat fetuses (14th, 17th, 18th, 19th and 21st day) was examined. In the prenatal stages the medullary blastema and an adjacent part of the primitive sympathetic trunk were also investigated. Tissues were fixed in ice-cold 4% paraformaldehyde in 0.1 M phosphate buffer (pH 7.2). Cryostat sections (10 μm in thickness) were stained by the indirect immunofluorescence technique. Rabbit antibodies to TH (isolated from human pheochromocytoma), DDC, DBH and PNMT (the latter three isolated from bovine adrenal medulla) were used. Sections incubated with serum of non-immunized rabbits were used as controls. In the adult adrenal medulla, two cell types can be distinguished. One cell type contains only TH, DDC and DBH. The other cell type contains PNMT in addition. It is concluded that these cells correspond to the noradrenaline-(NA-) and adrenaline-(A-)storing cells respectively. In all prenatal stages TH, DDC and DBH are found in the primitive sympathetic trunk, in the medullary blastema, and in the medullary cells which have migrated into the cortical “anlage”. PNMT is observed for the first time on the 18th day. Moreover, PNMT could only be demonstrated inside the adrenal gland. From these observations it is concluded that the capacity to synthesize NA is developed even before the “medullary” cells have reached the cortical “anlage”. On the contrary, the capacity to synthesize A seems to be acquired only after this contact is established. The hypothesis is put forward that this phenomenon might indicate the induction of PNMT by glucocorticoids secreted by the fetal cortex.
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  • 3
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    Cell & tissue research 200 (1979), S. 135-146 
    ISSN: 1432-0878
    Keywords: Arcuate nucleus ; Cytogenesis ; Synaptogenesis ; Neuropil ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphogenesis of the arcuate nucleus of the rat from the 15th fetal day to the 6th postnatal day was investigated light and electron microscopically. The arcuate neurons exhibit a gradual development after the 15th fetal day. All cytoplasmic constituents are present in these nerve cells already during the last days of gestation. Nevertheless, they are not fully differentiated at birth. The first synapse-like structures (presynapses) were observed in 17 day-old, the first synapses in 18 day-old fetuses. During the early postnatal period the number of presynapses decreases, but at the same time there is a gradual increase in the number of the relatively mature synapses. This process starts already during the last days of prenatal life. Although all structural elements of the arcuate nucleus of the adult rat appear to be present at birth, the extent of the neuropil area and the number of the presynapses indicate that the arcuate nucleus is still in a fairly undeveloped stage during the first postnatal days.
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  • 4
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    Cell & tissue research 200 (1979), S. 329-334 
    ISSN: 1432-0878
    Keywords: Median eminence ; Axon terminals ; Tanycytes ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The present ultrastructural study proves the existence of nerve terminals closely apposed to the plasmalemmata of tanycytes in the rat median eminence. Several of these “axo-tanycytic” endings display remarkable accumulations of agranular endoplasmic reticulum in the form of pleomorphic vesicles which are closely apposed on either side of the plasma membrane of each cell compartment. Some of these vesicular profiles give the impression of structural continuity across both membrane systems. This phenomenon is discussed in the context of being a potential substratum for communication between both cell compartments.
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  • 5
    ISSN: 1432-0878
    Keywords: Vomeronasal organ ; Membrane particles ; Cell contacts ; Freeze-etching ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The free surfaces and cell contacts in the epithelia of the vomeronasal organ of the rat were investigated by freeze-etching. The microvilli of receptor cells show a lower density of intramembranous particles (IMP) than the microvilli in the receptor-free epithelium. The ratio between the IMP on P and E-face is approximately 11∶1 in the receptor terminals, and 3.5∶1 in the cilia and microvilli of the receptor-free epithelium. Although atypical in length and only poorly equipped with rootlet fibers, the cilia of the receptor-free epithelium are furnished with typical ciliary necklace structures of up to 10 rows of membrane particles. Differences in the density of IMP on the P-faces of different cilia are probably due to continual ciliogenesis and also due to the different age of cilia in the receptor-free epithelium. Zonulae occludentes show different configurations in the neuroepithelium and in the receptor-free epithelium. In the former, they show a tendency to cross-link and form facet-like patterns, reflecting a constant morphology and relative stability for this apical region. In the receptor-free epithelium the junctional rows of zonulae occludentes display only loosely interconnected networks and a tendency to orient parallel to each other and to the free surface. In addition to zonulae occludentes, typical square aggregations of IMP are observed in the receptor-free epithelium. They are not exclusively restricted to the zone of intensive cell contacts by means of fine interdigitating cell processes, and their function has yet to be identified experimentally.
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  • 6
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    Cell & tissue research 200 (1979), S. 163-177 
    ISSN: 1432-0878
    Keywords: Gastrin cells ; Entero-endocrine cells ; Rat ; Cell isolation ; Pylorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A technique has been developed to obtain viable, isolated and enriched populations of gastrin cells (G-cells) from the rat stomach. Restricted tissue samples from a small area of the pyloric antrum known to be particularly rich in G-cells, were sequentially digested with pronase followed by mechanical agitation, to remove the epithelial cells. This technique resulted in a significant enrichment of G-cells (3–4 fold) since the surface epithelial cells and upper portions of the glands were discarded before the initial G-cell fraction was collected. These cells in suspension were then isolated from each other by gentle pipetting in a DNase containing solution and designated the crude preparation (CP). The G-cells were then purified further by separating the cells according to size by velocity sedimentation. The greatest concentration of G-cells (15–25 %) was found in the fraction containing cells with diameters of 10 to 12 μm. The effectiveness of the technique was evaluated by counting G-cells as identified by electron microscopy and immunofluorescence and assessing gastrin activity by radioimmunoassay. All three methods indicated that cell separation by gravity velocity sedimentation enriched the G-cell population 15–20 fold over their concentration in the CP. The combined techniques of selective pronase digestion followed by gravity velocity sedimentation resulted in an isolated cell preparation containing a 50–100 fold increase of G-cells over their normal distribution in the intact gastric mucosa. Since these isolated G-cells retain features indicating viability, their usefulness for in vitro studies is suggested.
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  • 7
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    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 367-372 
    ISSN: 1618-2650
    Keywords: Best. von Lanthaniden, Europium, Dysprosium, Erbium, Samarium in Uran ; Spektralphotometrie ; Atomabsorption ; Graphitofen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary Studies were conducted on the assay of Sm, Eu, Dy and Er separated from uranium using aqueous standards by electrothermal AAS with Massmann type graphite furnace. The working curves were found to be linear in the ranges Sm (1–10 μg/ml), Eu (0.05–0.6 μg/ml), Dy (0.1–0.8 μg/ml) and Er (0.1–1.0 μg/ml). The values obtained for synthetic samples agreed favourably with those obtained by emission spectrographic method. Experiments using pyrolytic carbon coated tubes with and without pretreatment by La, Ta and Y have shown an enhancement with treatment upto a maximum of 15% and improve the memory effect marginally. The effect of Ta treatment was found to be singularly useful in improving the general behaviour of Sm. The interference effects of lanthanides, other than the analyte, were found to be negligible. However, the presence of uranium was found to affect the absorbance. The absorbance of Eu was found to be nearly independent of uranium after an initial increase. On the other hand, the absorbance of other elements studied was found to drastically decrease after an initial enhancement. Detailed investigations of temperature dependence of absorbance were carried out using Eu, Dy and Er. The differences in the behaviour of these elements is attributed to probable differences in the modes of their atomization.
    Notes: Zusammenfassung Die Untersuchungen wurden mit Hilfe des Graphitrohrofens nach Maßmann durchgeführt. In folgenden Bereichen ergaben sich lineare Eichkurven: Sm 1–10 μg/ml, Eu 0,05–0,6 μg/ml, Dy 0,1–0,8 μg/ml, Er 0,1μ-1,0 μg/ml. Die aus synthetischen Proben erhaltenen Ergebnisse stimmten gut mit den durch Emissionsspektrographie erhaltenen überein. Versuche wurden mit Röhren mit pyrolytischen Kohlenstoffüberzug mit und ohne Vorbehandlung durch La, Ta und Y durchgeführt und ergaben eine bis 15%ige Steigerung durch die Behandlung sowie eine mäßige Besserung des Memoryeffektes. Eine Behandlung mit Ta war besonders für Sm vorteilhaft. Störungen durch andere Lanthanide waren vernachlässigbar. Uran beeinflußte jedoch die Absorption. Im Falle von Eu zeigte sich nach anfänglicher Zunahme fast eine Unabhängigkeit, während bei den anderen untersuchten Elementen nach anfänglicher Zunahme eine beträchtliche Abnahme auftrat. Mit Eu, Dy und Er wurde ebenfalls die Temperaturabhängigkeit der Absorption untersucht. Festgestellte Unterschiede im Verhalten werden auf unterschiedliche Atomisierung zurückgeführt.
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  • 8
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 284-284 
    ISSN: 1618-2650
    Keywords: Best. von Uran(VI) mit Chlorphosphonazo III ; Spektralphotometrie ; Trioctylamin-Extraktion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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  • 9
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 285-285 
    ISSN: 1618-2650
    Keywords: Best. von Phosphat in Ferrosilicium ; Spektralphotometrie ; Cer/Xylenolorange, indirekt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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  • 10
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 413-413 
    ISSN: 1618-2650
    Keywords: Best. von Kobalt mit Pyridin und Azid ; Spektralphotometrie ; Aussalzungsmittel, Mischkomplex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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  • 11
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 270-270 
    ISSN: 1618-2650
    Keywords: Best. von Cer(IV) ; Spektralphotometrie ; indirekt, Fe(III)-Resacetophenonoximat-Komplex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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  • 12
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    Fresenius' Zeitschrift für analytische Chemie 299 (1979), S. 264-266 
    ISSN: 1618-2650
    Keywords: Best. von Kohlenhydraten in Huminsäuren ; Spektralphotometrie ; Anthronmethode
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Eine modifizierte Anthronmethode zur Bestimmung des Kohlenhydratgehaltes in Fraktionen von Huminsäure-Blei(II)-Chelatverbindungen, die mit chemischen und gelchromatographischen Methoden getrennt wurden, wird beschrieben. Um die Störung der Methode durch die Absorption der Huminsäuren, die mit abnehmender Wellenlänge ansteigt, gering zu halten, wird die Extinktion des Anthron-Kohlenhydrat-Reaktionsproduktes bei 620 nm gemessen. Die Huminsäurekonzentration darf 0,1 g/dl nicht überschreiten. Da die molare Extinktion des Anthron-Reaktionsproduktes von der Art des Kohlenhydrates abhängt, wird der Kohlenhydratgehalt auf das Hauptkohlenhydrat des Huminsäurehydrolysats berechnet (d.h. Glucose).
    Notes: Summary A modified anthrone method is described for the determination of carbohydrates in fractions of lead(II)-chelate compounds of humic acids separated with chemical as well as gel-chromatographic methods. To reduce the disturbance of the method by the absorption of humic acids increasing with the decrease of wavelength, the absorbance of the anthronecarbohydrate reaction products is measured at 620 nm and the humic acid concentration is not allowed to exceed 0.1 g/dl. Because the molar absorptivity of the anthrone reaction-products depends on the type of carbohydrate investigated, the content is calculated for the main carbohydrate of the humic-acid hydrolysate (i.e. glucose).
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  • 13
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 366-370 
    ISSN: 1618-2650
    Keywords: Best. von Quecksilber, Silber mit Formazanen ; Spektralphotometrie ; chelatbildende Ionenaustauscher
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Darstellung substituierter Formazane und ihre chemische Fixierung an Cellulose, amino- und chlormethyliertem Polystyrol wird beschrieben. Die Kapazitäten der Austauscher liegen zwischen 0,05 mÄq/g (Cellulose) und 0,6 mÄq/g (Polystyrol). In neutralem Medium zeigen sie eine besondere Affinität zu Hg(II), Pd(II) und Ag(I), aber keine Affinität zu Cu(II). Weiterhin wurde eine spektrophotometrische Bestimmung von Hg(II) und Ag(I) mit dem wasserlöslichen Formazan (FII)-NO2 ausgearbeitet [Hg(II): ɛ546=23 000 l Mol−1 cm−1, Ag(I): ɛ546 =38 000 l Mol−1 cm−1].
    Notes: Summary The preparation of substituted formazans and their fixation on cellulose, amino- and chloromethylated polystyrene is described. The capacities of the exchangers vary from 0.05 meq/g (cellulose) to 0.6 meq/g (polystyrene). They show in neutral medium greater affinity to Hg(II), Pd(II) and Ag(I), but no affinity to Cu(II). Further, a spectrophotometric determination of Hg(II) and Ag(I) with the watersoluble formazan (FII)-NO2 has been worked out. [Hg(II): ɛ546=23 000 l Mol−1 cm−1, Ag(I): ɛ546=38 000 l Mol−1 cm−1].
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  • 14
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 356-360 
    ISSN: 1618-2650
    Keywords: Spektralphotometrie ; Mechanisierung, Prinzip, Optimierung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Das Prinzip der Automatisierung der photometrischen Analyse mit kontinuierlichem Reagentienfluß und die speziellen Vorteile der Verwendung von Bausteinen der Flüssigkeits-Chromatographie werden ausführlich diskutiert. Die Optimierung folgender Parameter wird besprochen: Verweilzeit (Reaktionszeit), Einspritzmenge, Pumpgeschwindigkeit, Säulenabmessungen, Partikeldurchmesser.
    Notes: Summary The principle of automation of photometric analysis by the continuous flow method and the particular advantages of the use of component parts of liquid chromatography are discussed in detail. The optimization of the following parameters is pointed out: residence (reaction) time, injection volume, pumping rate, column dimensions and particle diameter.
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  • 15
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 47-47 
    ISSN: 1618-2650
    Keywords: Best. von Vanadium in Stahl ; Spektralphotometrie ; Hydroxyphenyl-p-tolylbenzamidin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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  • 16
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 393-397 
    ISSN: 1618-2650
    Keywords: Best. von Tensiden in Wasser ; Spektralphotometrie ; Aniontenside, Reinigungsstufen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Aniontenside werden an Feststoffen der Gewässer wie auch der Kläranlagen adsorbiert und teilweise angereichert. Ihre analytische Bestimmung erfordert eine mehrstufige Vorarbeit. Sie führt über die Extraktion des Probengutes, die Abtrennung der Tenside von Störstoffen durch Ausblasen (grobe Vorreinigung) und die chromatographische Reinigung der Rohfraktion auf Kieselgelschichten. Die Konzentration der reinen Tensidfraktion kann colorimetrisch oder IR-spektrometrisch bestimmt werden.
    Notes: Summary Anion tensides are adsorbed on solids in surface waters and sewage treatment plants and enriched to some extent. Their analytical determination requires multi-stage preparations, including sampling, separation of the tensides from disturbing material by air stripping (rough preliminary cleaning), and chromatographic cleaning of the raw fraction on silica gel. The concentration of the pure tenside fraction can be determined colorimetrically or by way of IR spectrometry.
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  • 17
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    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 159-160 
    ISSN: 1618-2650
    Keywords: Best. von Vanadium(V) mit p-Hydroxybenzaldehyd und Hydroxyamidin ; Spektralphotometrie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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  • 18
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    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 158-158 
    ISSN: 1618-2650
    Keywords: Best. von Palladium, Ruthenium ; Spektralphotometrie ; Isonitrosodibenzoylmethan
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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  • 19
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    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 160-160 
    ISSN: 1618-2650
    Keywords: Best. von Ruthenium(III) mit 3-Hydroxy-3-(p-dimethylaminophenyl)-1-phenyltriazen ; Spektralphotometrie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
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  • 20
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    Cell & tissue research 200 (1979), S. 29-33 
    ISSN: 1432-0878
    Keywords: Magnocellular neurosecretory system ; Activation ; Rat ; Vasopressinergic neurons ; Oxytocinergic neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The activated hypothalamic magnocellular neurosecretory system of the rat was studied in tissue sections, double stained with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique. The results indicate that in animals with an activated hypothalamic magnocellular neuroendocrine system, as well as in normal animals, vasopressin and oxytocin are exclusively synthesized in separate vasopressinergic and oxytocinergic neurons.
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  • 21
    ISSN: 1432-0878
    Keywords: LH-RH neurons ; Hypothalamus ; Rat ; Immunohistochemistry ; Radioimmunoassay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The location of the perikarya of LH-RH neurons in the rat hypothalamus and their pathways to the median eminence were studied by immunohistochemistry and radioimmunoassay after placing stereotaxic electrolytic lesions in several parts of the hypothalamus. The principal location of the cell somata was found to be in the ventral part of the medial preoptic area; their pathways were classified into a main baso-lateral pathway and an accessory descending pathway branching off from the former. The main pathway was found to cross in the vicinity of the corresponding neuronal perikarya. The central median eminence and the dorsal and ventral walls of the tubero-infundibular sulcus of the caudal part of the median eminence are innervated mainly by the baso-lateral pathway. On the other hand, the rostral and most caudal portions of the median eminence are innervated principally by the descending pathway and have a subsidiary dual innervation. The projection of LH-RH neurons to the OVLT is believed to originate from perikarya adjacent to this circumventricular organ.
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  • 22
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    Cell & tissue research 198 (1979), S. 427-433 
    ISSN: 1432-0878
    Keywords: Arcuate nucleus ; Rat ; Hypothalamic deafferentation ; Synaptic plasticity ; Estrogen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to examine the effect of estrogen on the synaptic structures in the hypothalamic arcuate nucleus (ARCN), semi-quantitative studies were performed by counting synapses in an 18,000 μm2 area in the middle part of the ARCN in each brain. In ovariectomized female rats injected with 2 μg of estradiol benzoate (EB) for three weeks, the mean numbers of axodendritic and axosomatic synapses were not significantly different from those in the intact and ovariectomized controls. When the medial basal hypothalamus (MBH) including the ARCN was isolated by use of a Halász knife (MBH island), the mean number of axodendritic synapses was decreased to about half of the controls. However, EB treatment for three weeks from the day of surgery effectively restored the axodendritic synaptic population of the deafferented ARCN. This may suggest that estrogen has a facilitatory effect on axodendritic synapse formation in the deafferented ARCN, presumably by stimulating axonal sprouting and synaptic regeneration of intact axons in the MBH island.
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  • 23
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    Cell & tissue research 198 (1979), S. 441-454 
    ISSN: 1432-0878
    Keywords: Testis ; Rat ; Seminiferous tubule ; Transitional zone ; Fine structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An electron microscopic study was made on the structure of the testicular transitional zone (TZ) in the adult rat. The TZ proper consists of modified Sertoli cells, with only a few spermatogonia and macrophages, surrounding distally a very narrow lumen. The TZ Sertoli cells have nuclei with a somewhat coarser matrix and more peripheral heterochromatin than Sertoli cell nuclei of the nearby seminiferous tubules, and the electron density of the cytoplasm varies from cell to cell. Smooth endoplasmic reticulum is abundant, but usually there are also scattered ribosomal rosettes and an occasional profile of rough endoplasmic reticulum. Microtubules are very numerous in the columnar portion of the cell, and laminar structures seemingly joining the cell surfaces are sometimes seen. Lipid droplets and lysosomal structures are frequent cellular components in proximal TZ Sertoli cells. Empty intracellular vacuoles are abundant, sometimes arranged around areas of smooth endoplasmic reticulum. Occasionally, membrane-limited fine granules and vacuoles are seen within Sertoli cells and also in the TZ lumen, suggesting a possible secretory activity by these cells. The apical processes of the Sertoli cells form large vacuolar structures, and in the basal parts of the epithelium vacuoles with capillary-like appearance are frequently seen. Phagocytosis of germinal cells by the Sertoli cells occurs in the proximal region of the TZ. Round waste bodies in contact with the Sertoli cell apices protruding into the tubulus rectus, are also common. The tunica propria of the TZ is thickened and somewhat wrinkled, and in the proximal region the myoid cell layer loses its continuity and is replaced by fibroblasts. The epithelium of the tubulus rectus adjacent to the TZ consists of several overlapping epithelial cells. The typical junctional complexes between TZ Sertoli cells appear to be impermeable to the lanthanum tracer.
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  • 24
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    Cell & tissue research 199 (1979), S. 483-492 
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Rat ; Luteotroph cells ; Pimozide ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of pimozide, a dopamine receptor-blocking agent, were studied in the pars distalis of the rat. The animals received 100μg/100 g pimozide daily for 5, 10, 15, and 20 days. Pimozide induces striking ultrastructural changes after 5 days of treatment. The number of luteotroph (LTH) cells is significantly increased; they display characteristics of stimulation. The extrusion of granules into the intercellular space via exocytosis is frequently observed. The intercellular spaces are highly dilated, forming a lacunar system filled with an amorphous material, erythrocytes and involuted LTH cells. Transitional stages in the process of involution are observed in LTH cells. Luteotroph cells also form a syncytium. Twenty days after treatment the abovedescribed changes decrease in magnitude. The present findings suggest that pimozide stimulates the mechanism of synthesis and release in the luteotroph cells, an effect that is less evident with longer treatment.
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  • 25
    ISSN: 1432-0878
    Keywords: Pars distalis ; Graft ; Ultrastructure ; Prolactin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intact female rats received transplants of two hypophysial partes distales under the kidney capsule. The plasma levels of prolactin were determined, and the ultrastructure of the grafted gland was studied 15, 45 and 90 days after the operation. Although prolactin levels in the three experimental groups were significantly higher than those in control rats, a decrease in prolactin level was detected in the 45-day samples. Parallel ultrastructural changes suggest that between the 45th and 90th postoperative day a process is initiated leading to hyperplasia and hypertrophy of prolactotrophs.
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  • 26
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    Cell & tissue research 199 (1979), S. 271-279 
    ISSN: 1432-0878
    Keywords: Subsurface cisterns ; Neurons ; Paraventricular nucleus ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Structures identified as subsurface cisterns (SSC's) were found in neurons of the paraventricular nuclei of the rat hypothalamus. They appeared as cytoplasmic organelles consisting most often of stacks of parallel cisterns apposed to the neuronal plasmalemma. These SSC's were located in the interneurons of the parvocellular system, but not in neurosecretory cells and glial cells. SSC's were seen at zones of cytoplasm apposed to neuronal or glial cell processes, showing in some instances specific relationships with synaptic areas. The morphological features of these SSC's are described, and their possible functional significance is briefly discussed.
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  • 27
    ISSN: 1432-0878
    Keywords: Hypothalamo-hypophysial system ; Rat ; Tanycytes ; Ontogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The differentiation of tanycytes was studied light and electron microscopically during the perinatal period in rats, the time when functional connections between hypothalamus and hypophysis are established. The 3rd ventricle is slit-like between 16 and 18 days of the prenatal period. Its wall is formed by intensively proliferating matrix cells with apical processes, ovoid perikarya and a basal process. The ventral region of the 3rd ventricle becomes funnel-shaped on the 20th day of the prenatal period. As the cells differentiate, the apical process becomes shorter and broader. Moreover, on day 20 of prenatal life cells without apical processes appear. Their number increases during the postnatal period. The concentration of endoplasmic reticulum, mitochondria, polysomes, lipid droplets, dense bodies (lysosomes), lamellated and multivesicular bodies increases. Initially the cells are similar but from the 3rd day of postnatal life differentiation occurs in different regions of the infundibular recess. After the 5th day, there are no marked changes in the structure and distribution of these cells.
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    Cell & tissue research 201 (1979), S. 377-408 
    ISSN: 1432-0878
    Keywords: Median eminence ; Tanycytes ; Nerve tracts ; Regional organization ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structural organization of the rostral, lateral and postinfundibular regions of the median eminence (ME) of 5-day cyclic diestrous rats was studied with light and electron microscopic methods. The ependymal cells lining (i) the floor of the infundibular recess (IR) at rostral levels, (ii) the lateral extensions of the IR, and (iii) the floor of the premammillary recess appear to represent the same type of tanycyte ependyma (β1 tanycytes). In the entire width of the rostral and postinfundibular palisade regions, as well as in the lateral palisade region of the preinfundibular ME, the processes of the β1 tanycytes form a continuous cuff. This cuff separates the nerve endings from the blood vessels and the pars tuberalis. At this level, synaptoid contacts between neurosecretory axons and the ependymal cuff can be observed. The ultrastructural characteristics of the β1 tanycytes are described and their ependymal endings tentatively classified into three types. In the lateral regions of the ME, the Golgi study revealed the presence of two fiber systems: (i) one possessing a latero-medial trajectory and distributed in the subependymal region; (ii) the other formed by a loose longitudinal tract originating from neurons of the arcuate nucleus. Some functional implications of the cellular organization of the rat ME are discussed.
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    Cell & tissue research 201 (1979), S. 349-359 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Rat ; Somatostatin-containing neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rat hypothalamus was studied at the light microscopic level with the use of single and double immunocytochemical staining methods. It was shown that the rat supraoptic and paraventricular hypothalamic nuclei, and their accessory neurosecretory nuclei, do not contain magnocellular somatostatin neurons. The distribution of the hypothalamic parvocellular somatostatin cells is described. The parvocellular component of the rat hypothalamic paraventricular nucleus is, at least partly, composed of somatostatin cells: they form a fairly well circumscribed periventricular cell mass. The rat suprachiasmatic nuclei contain separate somatostatin neurons and vasopressin neurons. Scattered somatostatin cells are present in the entire arcuate nucleus. In addition to the periventricular somatostatin cells located in the preopticanterior hypothalamic area and in the arcuate nucleus, the rat hypothalamus also contains numerous scattered somatostatin cells located distant from the third ventricle.
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    Cell & tissue research 201 (1979), S. 93-99 
    ISSN: 1432-0878
    Keywords: Pituitary cell ; Gonadotrophs ; Culture ; Cell lines ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gonadotroph-rich cell lines were established from multipotential pituitary clonal cells (2A8) which were implanted under kidney capsule of hypophysectomized female rats. These cell lines secrete gonadotrophins (FSH and LH) continuously over two months after establishment; LHRH stimulated the secretion of hormones into the culture medium. Many of the cells reacted immunohistochemically to antiserum to FSH or LH, while a small number reacted to antiserum to prolactin or TSH. They did not contain normal secretory granules such as those of gonadotrophs in vivo.
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    Cell & tissue research 201 (1979), S. 499-502 
    ISSN: 1432-0878
    Keywords: Monoamine fluorescence ; Microfluorometry ; Computer-assisted correction ; Hypothalamus ; Rat
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    Topics: Biology , Medicine
    Notes: Summary In a circumscribed area of the preoptic periventricular nucleus of a male rat, formaldehyde-induced monoamine fluorophores modified by treatment with HCl vapors were investigated microfluorometrically (measurement of excitation peak ratio 370∶320 nm) in all fluorescent terminals and preterminals. Microfluorometric recordings of an individual fluorescent structure were performed without UV irradiation of neighboring fluorophores. Recorded data were sampled and corrected by a microcomputer (WangPCS II). 19 neuronal processes (axons) contained noradrenaline fluorophores; 11 contained dopamine fluorophores; 6 exhibited uncharacteristic excitation peak ratios; and in 9 recordings technical problems did not allow identification of the fluorophore content.
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    Cell & tissue research 202 (1979), S. 1-7 
    ISSN: 1432-0878
    Keywords: Matrix vesicles ; Normal bone ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The occurrence of vesicles in the extracellular matrix of alveolar bone of normal young rats was demonstrated by both ultrastructural and enzymatic studies. Transmission electron microscopy revealed abundant vesicles in the matrix. The presence of hydroxyapatite crystals, both within the vesicles and in the matrix, was affiliated with rupture of the vesicular membrane. Calcifying nodules were scarce. High levels of both specific and total activities of alkalineand pyrophosphatases were found in the fraction of isolated vesicles. This fraction also showed activities of different ATPases and acid phosphatase.
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  • 33
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Serotonin ; Quantitative light and electron microscopic radioautography
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    Notes: Summary Serotonin containing structures in the median eminence of the rat have been studied by quantitative light and electron microscopic radioautography following intraventricular infusion of tritiated 5-hydroxytryptophan. One hour after injection of the tracer the highest density of silver grains was recorded in the ependymal and external zones, especially in the lateral palisade zone. The proportion of labelled neurosecretory terminals was also larger in the lateral palisade zone (29%) as compared with the medial palisade zone (13%), although the mean number of developed silver grains per one terminal was higher in the latter. On the average, 16% of neurosecretory terminals sequestered radiolabelled 5-hydroxytryptophan in the external zone of the rat median eminence. It is suggested that serotonin, like catecholamines, is discharged from neurosecretory terminals localized in the external zone and via the portal circulation affects the function of the anterior pituitary. The sites of origin of serotoninergic structures of the median eminence as well as the possible role of monoamine (catecholamine and indolamine) neurohormones in a dual peptidergic and monoaminergic control of anterior pituitary functions are discussed.
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    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 45-45 
    ISSN: 1618-2650
    Keywords: Best. von o-Dichlorbenzol ; Spektralphotometrie ; UV
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    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 46-46 
    ISSN: 1618-2650
    Keywords: Best. von p-Methylaminophenolsulfat, Metol ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 406-407 
    ISSN: 1618-2650
    Keywords: Best. von Ligninsulfonsäure, Huminsäure in Wasser ; Spektralphotometrie ; UV
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    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 383-385 
    ISSN: 1618-2650
    Keywords: Best. von Bor in Silicaten ; Spektralphotometrie ; Pyrohydrolyse, Carminsäure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary This simple method for the determination of boron takes a total time of 20 min. Samples are mixed with CaF2 suprapur in the ratio 3∶1 and pyrohydrolized in a Leco induction furnace for 15 min under steam of H2O. The BF3 liberated is collected in a NaOH-Na2CO3 solution (10 g NaOH +1 g Na2CO3 per liter). This solution is filled up to 200 ml with twice distilled water; 2 ml of this solution is mixed with conc. sulphuric acid and carminic acid solution and filled up to 50 ml. The absorption is measured by a Zeiss Elko II photometer with filter S 59. Analyses of four internations reference samples show excellent precision with a relative standard deviation of less than 5% (e.g. for a boron content of 2.1 ppm in granite G-2).
    Notes: Zusammenfassung Die Borbestimmung mit dieser schnellen und einfachen Methode benötigt ca. 20 min. Die Proben werden mit CaF2 Suprapur im Verhältnis 3∶1 vermischt und in einem Leco-Induktionsofen 15 min unter Einleitung von Wasserdampf pyrohydrolysiert. Das entstandene BF3 wird in einer NaOH-Na2CO3-Lösung(10 g NaOH+1 gNa2CO3pro Liter) aufgefangen. Diese Lösung wird mit zweifach destilliertem Wasser auf 200 ml aufgefüllt; 2 ml dieser Lösung werden mit konz. Schwefelsäure und Carminsäure-Lösung versetzt und auf 50 ml aufgefüllt, bevor ihre Absorption mit einem Zeiss — Elko II — Photometer mit Filter S 59 gemessen wird. Analysen von 4 internationalen Referenzproben zeigen eine hohe Präzision mit einer relativen Standardabweichung von weniger als 5% (z. B. für einen Gehalt von 2,1 ppm Bor im Granit G-2 des USGS).
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    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 407-408 
    ISSN: 1618-2650
    Keywords: Best. von N-p-Tolylbenzohydroxamsäure ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 296 (1979), S. 414-415 
    ISSN: 1618-2650
    Keywords: Best. von Quecksilber(II) mit 3-Methyl-5-pyrazolon-4-dithiocarbonsäure ; Spektralphotometrie
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  • 40
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    Cell & tissue research 197 (1979), S. 443-451 
    ISSN: 1432-0878
    Keywords: Ameloblasts ; Cell death ; Incisors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The migration of the ameloblasts in the continuously erupting incisors of the rat is accompanied by cell loss. Ameloblasts degenerate near the mesial and lateral cemento-enamel junctions in the secretory zone and in the middle two thirds of the region of postsecretory transition, degeneration being most marked where these areas merge. These findings support the hypothesis that the prism decussation in the enamel results from alternating transverse rows of secretory ameloblasts sliding past each other whilst elaborating their rods. The distribution of the degenerating cells suggests, however, that the sliding cell rows are not exactly transverse but arcuate, with the opening facing incisally. The progress of structural alterations of the nuclei in the degenerating ameloblasts appears to follow the pattern earlier described in vinblastine-damaged ameloblasts.
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  • 41
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    Cell & tissue research 198 (1979), S. 145-158 
    ISSN: 1432-0878
    Keywords: Dorsal prostate gland ; Rat ; Apocrine secretion ; Prolactin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rat dorsal prostate epithelium was studied in intact adult animals, in animals castrated for three days and in rats after inhibition of prolactin secretion. Thin sections, electron-microscopic autoradiographs and freeze-fracture replicas were used to analyze the process of apocrine secretion in this gland. The rough endoplasmic reticulum and the Golgi apparatus of the secretory cells are well developed, but secretory granules are absent. The only sign indicating release of secretory material is the appearance of blebs originating from the apical plasma membrane. Freeze-fracture replicas of the apical plasma membrane reveal that the blebs develop randomly from the bases of microvilli-like protrusions. In vitro pulse labeling of the proteins using 3H-leucine resulted in a labeling of the apical blebs. A post-castration period of three days was sufficient to reduce drastically the number and size of the apical blebs concomitant with regressive changes of the cell. Suppression of prolactin secretion for three weeks by application of lisuride, a synthetic ergot alkaloid, also induced regressive changes in the secretory cells. The apical blebs were still present, but they were shrunken and their content appeared condensed. These experimental conditions proved that the apical blebs are closely related to the functional activity of the cells and are interpreted as true apocrine secretion in the rat dorsal epithelium.
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    Cell & tissue research 203 (1979), S. 223-229 
    ISSN: 1432-0878
    Keywords: Nuclear inclusions ; Neurons ; Paraventricular nucleus ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This paper deals with the ultrastructure of two types of intranuclear inclusions, “microfilamentous spindle-shaped” and “crystalloid”, present in paraventricular nucleus neurons of adult normal rats. These inclusions appear occasionally in some non-secretory neurons of the parvocellular system, but have never been seen in neurosecretory cells of the magnocellular system. The microfilamentous spindle-shaped inclusions show a close spatial relationship with the granulofibrillar body and interchromatin granules. The distribution and functional significance of such structures are discussed in the light of recent ultrastructural and biochemical studies on nuclear inclusions.
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  • 43
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Catecholamines ; Quantitative light and electron microscopic radioautography
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    Topics: Biology , Medicine
    Notes: Summary By means of light and electron microscopic radioautography a quantitative study of the regional distribution of catecholamines in the median eminence of the rat was carried out. One hour after intraventricular injection of 3H-dopamine the highest radioautographic reaction was recorded in the external zone, especially in the lateral palisade zone where many neurosecretory terminals are separated from the basal lamina of the portal pericapillary space by a glial “cuff”. This area showed the highest percentage (52%) of labelled catecholamine containing neurosecretory terminals as well as the maximal silver grain density per one terminal. In the medial palisade zone where direct neurovascular contacts with the capillary loops prevail, only 27 per cent of neurosecretory terminals were found to harbour tritiated dopamine. On the average 35 per cent of neurosecretory terminals in the median eminence of the rat contain catecholamines (both dopamine and noradrenaline). Pretreatment of animals with reserpine strongly reduced the binding of the label. Per cent of labelled neurosecretory terminals as well as grain density over terminals were decreased in both the medial and lateral palisade zones, although to a lesser degree in the latter. The site of origin of catecholamine fibers as well as the mode of catecholamine action at the level of the median eminence are discussed.
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  • 44
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    Cell & tissue research 204 (1979), S. 127-140 
    ISSN: 1432-0878
    Keywords: Somatostatin-like activity ; Retina ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A somatostatin-like substance is demonstrated by light microscopic immunohistochemistry (PAP-method) in perikarya and cell processes of the retina of adult and infant rats. These perikarya are identified according to their size, arrangement and distribution. Each of the first two neuronal orders (receptors, bipolar cells, ganglionic cells) of the visual pathway can be associated with retinal cells reacting positively with anti-somatostatin. In the adult rat, perikarya and processes of (i) horizontal cells, (ii) amacrine cells and (iii) large neurons in the ganglionic layer are specifically labeled. The staining of middle-sized and small ganglion cells is probably caused by the close attachment of labeled fibers to non-reacting cells. Postnatally, the immunoreactive elements develop in parallel to the differentiation of the corresponding retinal layers. It is discussed whether the three types of retinal cells containing a somatostatin-like substance provide an inhibitory system to each of the two orders of retinal neurons.
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    Cell & tissue research 196 (1979), S. 147-151 
    ISSN: 1432-0878
    Keywords: Submaxillary salivary gland ; Secretory granules ; Glycoproteins ; Effect of heat ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Secretory granule area and glycoprotein concentration of the saliva in the submaxillary gland of rats were measured during various stages of acclimation to heat at 34±1° C. Granule size decreased by 18% during the first five days of heat acclimation (0.025〈p〈0.05) after which period it increased to reach 118% of the control levels after 28 days (p〈0.05). Glycoprotein concentration in the saliva of stimulated glands rose above control levels, reaching a maximum between the 2nd and 5th day of acclimation (p〈0.05). It was concluded that the initial decrease in granule size reflects a decrease in glycoprotein content following an increase in salivary flow known to occur at high ambient temperatures. The subsequent increase in granule size is considered an adaptation of the gland to continuous stimulation. The rise in salivary glycoprotein concentration suggests increased efficiency of the secretory mechanism.
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  • 46
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Median eminence ; Intraependymal cisternae ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Structure, three-dimensional arrangement and ontogeny of large intracellular cisternae located in the median eminence region of the rat hypothalamus were studied using toluidin-blue stained semithin sections and electron microscopy. The cisternae occur along the projections of ependymal cells lining the ventral portion of the third ventricle (infundibular recess). Small cisternae can be seen close to the ventricle, whereas larger ones, divided into smaller compartments by thin septa, cluster near the surface of the hypothalamus. The cisternae are encompassed by a thin layer of cytoplasm to which axon terminals containing synaptic and dense core vesicles are closely related. Cisternae are arranged around the median eminence in a characteristic pattern. They occupy the midline in the retrochiasmatic area, flank both margins of the median eminence and extend caudally behind the origin of the pituitary stalk. The cisternae appear first between the 15th and 17th postnatal days. At about the 30th day their size and distribution resemble the situation observed in adult animals. The ependymal cisternae are suggested to be closely related to the luteinizing-hormone releasing-hormone (LH-RH)-containing fibers.
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  • 47
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    Cell & tissue research 197 (1979), S. 337-346 
    ISSN: 1432-0878
    Keywords: Development ; Median eminence ; Neurohypophysial hormones ; Corticotrophin releasing factor ; Immunoperoxidase histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transverse sections of the median eminence from fetal and neonatal rats were examined by the immunoperoxidase technique to detect the presence of oxytocin, vasopressin and neurophysin. Neurophysin was observed in the 18-day fetus. Vasopressin and oxytocin were not detected until after birth, on the 4th and 8th days respectively. There was an accumulation of material crossreactive with neurophysin and vasopressin antibodies in the palisade layer of the median eminence between the 4th and 9th days after birth. This distribution of immunoreactive material in the palisade layer was suggestive of neurosecretory substances localized in two fibre tracts on either side of the median eminence. The data are consistent with the accumulation of corticotropin releasing factor and an associated neurophysin in this area. It is suggested that the accumulation of material occurs because of the relative immaturity of the capillary loops that constitute the primary plexus of the hypophysial portal system.
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    Cell & tissue research 196 (1979), S. 237-247 
    ISSN: 1432-0878
    Keywords: Liver ; Kupffer cells ; G6PDH activity ; Histochemistry ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The aim of this study was to identify the G6PDH-active sinusoidal cells in the rat liver described by Rieder et al. (1978). Because of their number and distribution in the liver parenchyma, endothelial cells and pit cells could be excluded. Fat-storing cells were specifically marked by vital staining with vitamin A and identified by fluorescence microscopy. Kupffer cells could be detected after vital staining with carmine. Both staining methods allowed a subsequent incubation for the demonstration of G6PDH activity in the same unfixed cryostat section. Whereas more than 80% of the fluorescent particles were found outside the enzyme-positive cells, all G6PDH-active cells contained carmine particles. After counting the G6PDH-active cells, an estimation of 0.217 × 108 cells/g liver tissue was obtained. The results indicate that high G6PDH activity is common to all Kupffer cells, and is therefore a highly specific marker enzyme for this class of sinusoidal liver cells.
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  • 49
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Hypothalamo-hindbrain pathway ; Rat ; Blood pressure ; Milk ejection
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    Topics: Biology , Medicine
    Notes: Summary 1. In lactating rats and in rats deprived of water, the amount of neurosecretory material in the fibres of the neurosecretory hypothalamohindbrain pathway exceeds that in untreated control animals. Under these experimental conditions the pathway and its target regions can be well analysed by means of fluorescence and electron microscopic methods. 2. The axons belonging to the hypothalamo-hindbrain pathway originate from perikarya located in the caudal portion of the nucleus paraventricularis and also from a small group of perikarya in the caudo-lateral hypothalamus. On the way to the hindbrain the neurosecretory fibres join other fibre bundles of the mid- and hindbrain. 3. In the hindbrain most of the neurosecretory fibres terminate in the area of the nucleus tractus solitarii and in the area of the dorsal column nuclei. The axon terminals form synapses with other neurones. 4. Using cytochemical methods at the ultrastructural level (Naumann and Sterba, 1976), the authors were able to prove that the vesicles in the exohypothalamic fibres and in their synaptic terminals contain the same sort of material as the neurophysin vesicles in the posterior lobe of the hypophysis. 5. The most distinct increase in neurophysin was observed in lactating females which were separated from their sucklings after a normal lactation period of 15 days and killed four days thereafter, and in rats deprived of water for different time periods. 6. The relationship of the neurosecretory hypothalamo-hindbrain pathway to the nucleus tractus solitarii and to the dorsal column nuclei suggests that, functionally, there may be a correlation between the system of blood-pressure control and the milk ejection reflex.
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 286-286 
    ISSN: 1618-2650
    Keywords: Best. von Aminen mit Isothiocyanatodioxotolyldihydrobenzisochinolin ; Spektralphotometrie
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    Topics: Chemistry and Pharmacology
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 285-285 
    ISSN: 1618-2650
    Keywords: Best. von Eisen(III), Chrom(VI) mit Helasolviolett 4R ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 119-121 
    ISSN: 1618-2650
    Keywords: Best. von Wolfram(VI) mit Thioglykolsäure ; Spektralphotometrie ; Chelatbildung, Carbonsäuren
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung W(VI) bildet mit Thioglykolsäure und Glykolsäure mäßig stabile Fünfringchelate der Zusammensetzung WR2, mit Glycin ein sehr schwaches WR. Chelate mit den Sechsringbildnern 3-Mercaptopropionsäure und o-Mercaptobenzoesäure sind nicht nachweisbar. Das Thioglykolsäurechelat kristallisiert aus Methanol als gelbes Na-Salz WO2(SCH2COONa)2·2CH3OH und ist mit Di-phenylguanidin als Ionenpaar in Butanol extrahierbar. Die photometrische Wolframbestimmung mit Thioglykolsäure in wäßriger Lösung erreicht eine Bestimmungsgrenze von $$\underline c $$ = 0,92 ppm W (P=99,9%;M=2) und eine Standardabweichung vons=0,24 ppm W (f=21).
    Notes: Summary W(VI) forms moderately stable, five-membered ring chelates of the composition WR2 with thioglycolic and glycolic acid, and a very weak WR with glycine. Chelation with the six-ring forming 3-mercaptopropionic acid and o-mercaptobenzoic acid could not be detected. The chelate with thioglycolic acid crystallizes from methanol as the yellow sodium salt WO2(SCH2COONa)2·2CH3OH and can be extracted into butanol as an ion pair with diphenylguanidine. The photometric determination of tungsten with thioglycolic acid has a determination limit of $$\underline c $$ = 0.92 ppm W (P=99.9%;M=2) and a standard deviations=0.24 ppmW (f=21).
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 122-124 
    ISSN: 1618-2650
    Keywords: Best. von Sulfat in Umweltmaterial ; Wasser ; Spektralphotometrie ; Durchflußsystem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary Sulphate in various environmental samples was determined by measuring the optical absorbance upon reaction with the barium(II) dimethylsulphonazo(III) complex. The measurement took place in a flow-through system. Interferences from phosphate, metal ions and others were eliminated. The results of a turbidimetric measurement, a spectrophotometric measurement with thorin, an automatic titration and the proposed method are compared. The latter allows the determination of sulphate in the range of 1.4–60 μmol·l−1. The standard deviation is 0.3–0.6 μmol·l−1, depending on the type of sample (water) analysed. A determination takes 1.5min.
    Notes: Zusammenfassung Sulfat wurde in verschiedenen Umweltproben durch Messung der Extinktion nach Reaktion mit dem Barium(II)-dimethylsulfonazo(III)-komplex im Durchflußsystem bestimmt. Störungen von Phosphat, Metallionen, u.a. wurden beseitigt. Die Ergebnisse einer turbidimetrischen, einer photometrischen, einer automatischen Titration und der vorgeschlagenen Methode werden verglichen. Die Methode ermöglicht die Sulfatbestimmung im Bereich von 1,4–60 μmol·l−1. Die Standardabweichung beträgt 0,3–0,6 μmol· l−1 je nach Typ des Probematerials (Wasser). Eine Bestimmung erfordert 1,5min.
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 271-271 
    ISSN: 1618-2650
    Keywords: Best. von Blei in Wasser, Abwasser, Staub ; Spektralphotometrie ; Dithizon
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 413-413 
    ISSN: 1618-2650
    Keywords: Best. von Platin(IV) mit Chlorpromazin ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 419-419 
    ISSN: 1618-2650
    Keywords: Spektralphotometrie ; Bouguer-Lambert-Beersches Gesetz, neues Konzept
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    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 160-160 
    ISSN: 1618-2650
    Keywords: Best. von Phenothiazinen ; Spektralphotometrie ; Silicowolframsäure
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 43-44 
    ISSN: 1618-2650
    Keywords: Best. von Salicylaldehyd ; Spektralphotometrie ; konz. Schwefelsäure
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 46-46 
    ISSN: 1618-2650
    Keywords: Best. von Osmium mit N-Benzoyl-o-tolylhydroxylamin ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 294 (1979), S. 415-416 
    ISSN: 1618-2650
    Keywords: Best. von Albumin in Serum ; Spektralphotometrie ; Isothiocyanatodioxo-tolyldihydro-benzisochinolin, Rinderserum
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    Fresenius' Zeitschrift für analytische Chemie 299 (1979), S. 128-128 
    ISSN: 1618-2650
    Keywords: Best. von Ruthenium mit 2-Methyl-1,4-naphtochinon-monoxim ; Spektralphotometrie ; Extraktion
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    Fresenius' Zeitschrift für analytische Chemie 295 (1979), S. 412-413 
    ISSN: 1618-2650
    Keywords: Best. von Palladium(II), Ruthenium(III) mit Isonitrosobenzoylacetone ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 297 (1979), S. 384-387 
    ISSN: 1618-2650
    Keywords: Best. von Uran ; Spektralphotometrie ; Spuren, Extraktion mit Triphenylarsinoxid in Chloroform
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wurde eine einfache, vielseitig anwendbare spektralphotometrische Uranbestimmung für U6+-Mengen bis in den ng-Bereich ausgearbeitet, bei der über 60 Kationen und etwa 20 Anionen in weiten Grenzen nicht stören. Das mit Triphenylarsinoxid in CHCl3 aus der zu untersuchenden Lösung extrahierte Uran wird mit oxalsäurehaltiger 5,5 M HClO4 zurückextrahiert und in den Arsenazo III-Komplex überführt. Die mit diesem Schritt verbundene Aufkonzentrierung erlaubt noch bis zu 0,01 μg Uran in 200 ml Ausgangslösung spektralphotometrisch bei 655 nm zu bestimmen. Im günstigsten Arbeitsbereich beträgt die relative Standardabweichung ±1%. 4 Probelösungen können in 1 h analysiert werden.
    Notes: Summary A simple and versatile spectrophotometric method for the determination of uranium down to the μg range was worked out. About 60 cations and 20 anions were found not to cause interferences in a wide concentration range. U6+ is extracted with triphenylarsine oxide in chloroform, back-extracted with 5.5 M perchloric acid containing oxalic acid and converted to the arsenazo III-complex. The concentration step involved allows the spectrophotometric determination of 0.01 μg of uranium in 200 ml of original solution at 655 nm. A standard deviation of ±1 % can be achieved and it is possible to analyse about 4 solutions per hour.
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    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 156-157 
    ISSN: 1618-2650
    Keywords: Best. von Sulfat in Wasser ; Spektralphotometrie ; Ionenaustausch, Dimethylsulfonazo(III)
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    Fresenius' Zeitschrift für analytische Chemie 298 (1979), S. 150-154 
    ISSN: 1618-2650
    Keywords: Best. von Kupfer mit Fluoronen ; Spektralphotometrie ; Übersicht über die Fluorone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Fluorone, Verbindungen des 2,3,7-Trihydroxyisoxanthenons-(6), eignen sich als empfindliche Reagentien für die spektralphotometrische Analyse zahlreicher Metallionen im sichtbaren Teil des Spektrums. Neben einigen grundsätzlichen Anmerkungen zur Herstellung, zu den Eigenschaften und Reaktionen der Fluorone mit Metallionen wird die Verwendung des Cyclohexylfluorons (CHF) für die photometrische Bestimmung von Cu(II)-Ion beschrieben; hierbei ergibt sich ein molarer Extinktionskoeffizient von 191000 l/Mol · cm und eine Standardabweichung von ±0,2 ng/ml. Der Anwendungsbereich liegt bei 6–60 ng Cu/ml. Bi, Fe(II/III) und Sb müssen zuvor abgetrennt werden.
    Notes: Summary Fluorones, derivates of 2,3,7-trihydroxyisoxanthenone-(6), are sensitive reagents for the spectrophotometric determination of many metal ions in aqueous solution. Besides some principal remarks on the synthesis, properties and reactions of fluorones, the application of cyclohexylfluorone for the determination of Cu(II) ion is described in detail. This method is applicable in the concentration range 6–60 ng of Cu/ml. The molar absorptivity is 1910001/Mol · cm and the standard deviation is ±0.2 ng/ml. Bi, Fe(II, III) and Sb have to be separated prior to the determination.
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    Calcified tissue international 25 (1978), S. 75-83 
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
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    Fresenius' Zeitschrift für analytische Chemie 293 (1978), S. 416-416 
    ISSN: 1618-2650
    Keywords: Best von Vitamin D2 ; Spektralphotometrie ; HCl, Tetrachloräthan
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    Fresenius' Zeitschrift für analytische Chemie 293 (1978), S. 416-416 
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    Keywords: Best. von Pikrinsäure ; Spektralphotometrie ; Zink und Ammoniumchlorid
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    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 43-44 
    ISSN: 1618-2650
    Keywords: Best. von Uran(VI) mit Arsenazo III ; Spektralphotometrie ; starksaure Lösung
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    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 46-47 
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    Keywords: Best. von Thallium(I), Dimethylthalliumverbindungen ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 233-235 
    ISSN: 1618-2650
    Keywords: Spektralphotometrie ; Ableitungen höherer Ordnung, Analogdifferenzierer, Derivativverfahren
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    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wird über eine neu entwickelte Analog-Recheneinheit berichtet, mit der man Ableitungen von Spektren und anderen Meßsignalen erstmalig bis zur 7. Ordnung on-line verwirklichen kann. Wie die Prüfungen ergaben, ist die optimale Auflösung in den meisten Fällen mit der 4. Ableitung erreicht. Dann sind nämlich alle Schultern und Wendepunkte der Kurven in bipolare Signale übergeführt. Eine Aufstellung der wichtigsten bisherigen Anwendungsgebiete wird gegeben.
    Notes: Summary This report deals with a newly developed analogue computing accessory by which derivations of spectra and other electric signals up to the seventh order were realized on-line. A thorough study of this apparatus showed that in most cases fine-resolving is reached by the fourth derivation. In this case, all shoulders and points of inflections are resolved to bipolar signals. A number of examples for applying derivative spectrophotometry of higher order (DSHO-method) is also given.
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    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 400-402 
    ISSN: 1618-2650
    Keywords: Bestimmung von Meclozin, Pyridoxin in pharmazeutischen Produkten ; Spektralphotometrie ; Orthogonalfunktion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary A rapid spectrophotometric method for the analysis of tablets containing the title compounds without preliminary separation is developed. Thus, pyridoxine is determined by measurement at λ max while the six-points quadratic orthogonal polynomial has been used to determine meclozine. The mean percentage recoveries (8 determinations) were found to be 101.71±0.64 and 99.77±0.62% (P=0.05) for meclozine and pyridoxine hydrochlorides, respectively. Neither the Vierordt's nor the absorbance ratio methods gave accurate results as the proposed method. The method was applied successfully to the analysis of market preparations.
    Notes: Zusammenfassung Es wurde ein Verfahren zur schnellen Bestimmung der beiden Verbindungen ohne Vortrennung ausgearbeitet. Pyridoxin wird durch Messung beim Absorptionsmaximum von 292 nm bestimmt, Meclozin wird mit Hilfe eines quadratischen Sechspunkte-Orthogonalpolynoms berechnet. Die Wiederfindungsrate (8 Bestimmungen) lag bei 101,71±0,64 bzw. 99,77±0,62% (P=0,05). Vergleichsbestimmungen nach der Methode von Vierordt und dem Verfahren der Extinktionsverhältnisse gaben weniger genaue Resultate. Die vorgeschlagene Methode wurde mit gutem Erfolg auf handelsübliche Präparate angewendet.
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    Fresenius' Zeitschrift für analytische Chemie 293 (1978), S. 220-221 
    ISSN: 1618-2650
    Keywords: Best. von Magnesium ; Spektralphotometrie ; Trimethin-Reagentien aus Aminochalkogenuracilen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Bekanntlich werden Trimethinfarbstoffe, als Reagentien für die photometrische Magnesiumbestimmung, durch die Kondensation von Malonaldehyd und Barbitursäure bzw. ihren Derivaten hergestellt. Auf ähnliche Weise erhält man mit 4(6)-Amino(2)-chalkogeno-uracilen und Malonaldehyd die Ammoniumsalze der Trimethinfarbstoffe, die sich ohne weitere Aufarbeitung als Reagentien für die photometrische Bestimmung einsetzen lassen. Die Herstellung der Verbindungen wird beschrieben.
    Notes: Summary It is known that trimethine dyes used for the photometrie determination of magnesium ions can be prepared by the condensation of malonicaldehyde with barbituric acid or its derivatives; In a similar way it is possible to use 4(6)-amino-2-chalcogeno-uracils giving with malonicaldehyde ammonium salts of the trimethine dyes, which are suited for the photometric determination without further manipulations. The preparation is described.
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  • 74
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    Keywords: Best. von Nickel, Kobalt mit 2-Carboxy-2′-hydroxy-3′,5′-dimethylazobenzol-4-sulfonsäure ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 302-303 
    ISSN: 1618-2650
    Keywords: Best. von Aldehyden, aromat. mit Barbitursäure ; Spektralphotometrie. Best. von Barbitursäure mit p-Dimethylaminobenzaldehyd ; Spektralphotometrie
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    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 359-361 
    ISSN: 1618-2650
    Keywords: Best. von Uran in Wasser ; Spektralphotometrie ; Arsenazo, Fällg. mit Al-Phosphat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Zur schnellen und genauen Bestimmung von Uranspuren in natürlichen, auch salzhaltigen Wässern, wird Uran durch Spurenfällung mit Aluminiumphosphat abgetrennt. Durch Auflösen des mit Zinkpulver vermengten Niederschlages erfolgt Reduktion zu U(IV), das mit Arsenazo III bestimmt wird. Der Extinktionskoeffizient beträgt 97000 cm2/Mol.
    Notes: Summary For the precise and accurate determination of uranium in natural, even saline, waters, it is separated by coprecipitation with Al-phosphate. The precipitate is mixed with zinc powder, dissolved and thus reduced to U(IV), which is determined with Arsenazo III. The molar absorptivity is 97000 cm2/mol.
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  • 77
    ISSN: 1618-2650
    Keywords: Best. von Phosphat neben Silicium, Arsen, Germanium ; Spektralphotometrie ; Extraktion mit Benzophenon, Molybdatmethode
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary A new type of separation of phosphate ion, along with its spectrophotometric determination, was established by liquid-liquid extraction, where the yellow heteropoly acid formed by the reaction with ammonium molybdate in acid solution is quantitatively extracted into molten benzophenone at a temperature of about 60° C. When cooled down to room temperature, the benzophenone extract converts from the liquid state to the solid state. The resulting solidified extract is dissolved in methyl propionate, and the phosphate ion in the solvent is determined spectrophotometrically by the blue heteropoly acid method. Possible interference by Si, As and Ge is eliminated by the separation procedure.
    Notes: Zusammenfassung Bei dem beschriebenen Verfahren wird die mit Ammoniummolybdat in saurer Lösung gebildete gelbe Heteropolysäure bei 60° C in geschmolzenes Benzophenon extrahiert. Dieses wird durch Abkühlen verfestigt, in Methylpropionat gelöst und in dieser Lösung das Phosphat spektralphotometrisch als blaue Heteropolysäure bestimmt. Si, As und Ge, die ebenfalls mit Molybdat reagieren, werden durch die Extraktion abgetrennt.
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    Cell & tissue research 189 (1978), S. 155-166 
    ISSN: 1432-0878
    Keywords: Levator ani muscle ; Rat ; Neuromuscular junction ; Castration ; Testosterone effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the neuromuscular junction (n.m.j.) of the androgen-sensitive levator ani muscle was studied in normal adult male rats, in 8-month-old rats castrated at the age of one month and in castrated rats treated with testosterone propionate (TP). Castration does not result in significant changes of the n.m.j. The density of synaptic vesicles and the postsynaptic junctional folds remain practically normal in spite of marked atrophy of the muscle. TP administration for 7 days results in marked changes in preand postsynaptic structures. There is slow progressive depletion of synaptic vesicles, appearance of cisternae and coated vesicles in axon terminals, and coalescence of coated vesicles with the plasma membrane. Coated vesicles are also found inside Schwann cells and among junctional folds. Dense core vesicles appear both in the axon terminals and in the postsynaptic area. Collateral sprouting of terminal axons with the formation of new immature junctions is observed. After 35 days of TP administration depletion of synaptic vesicles continues. Glycogen β-particles, mostly freely dispersed, occasionally seen in axon terminals 7 days after TP administration, subsequently increase in number. In the endplate zone of the muscle fibre increased protein synthesis is indicated by a rapid increase in ribosomes and irregularly located myofilaments and myofibrils. The appearance of n.m.j. after testosterone administration resembles that described after nerve stimulation; the degree of change is however less pronounced.
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    Cell & tissue research 189 (1978), S. 277-286 
    ISSN: 1432-0878
    Keywords: Maternal adrenalectomy ; Rat ; Influence on the adrenals of newborn animals ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Maternal adrenalectomy at 7 or 14 days of gestation produced increased cell necrosis within zona reticularis cells on the day of birth and at 24 or 48 h after birth. Small remnants or large portions of adrenocortical cells were present within macrophages. In otherwise normal adrenocortical cells, lipid droplets were incorporated within some mitochondria. Autophagocytosis of single mitochondria was observed within adrenocortical cells. Undoubtedly ultrastructural changes represent stimulation of adrenocortical cells in neonatal rats in response to maternal adrenalectomy.
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    Cell & tissue research 191 (1978), S. 501-506 
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Ultrastructure ; Perivascular space ; Hormonerelease ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes from rats subjected to neurohypophysial hormone-releasing stimuli were examined electron microscopically following fixation in 4 % tannic acid in 2.5 % glutaraldehyde. This fixation allowed the delineation of the perivascular space in the neural lobe tissue. Measurement of the area of the perivascular space showed that it was significantly increased in the rats subjected to vagal stimulation and intraarterial calcium ions compared to the control rats. The rats which had been subjected to haemorrhage as a hormonereleasing stimulus did not show any significant change in the area of the perivascular space. The significance of these findings in relation to hormone release is discussed.
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    Cell & tissue research 191 (1978), S. 507-512 
    ISSN: 1432-0878
    Keywords: Odontoblasts ; Osteoblasts ; Cementoblasts ; Intercellular attachments ; Electron microscopy (SEM/TEM) ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osteoblasts of the young rat cranium, and cementoblasts and odontoblasts of young rat molars were prepared by ethanol freeze-fracture prior to critical point drying for scanning electron microscopy (SEM) as well as conventional transmission electron microscopy (TEM) techniques. Critical point drying causes shrinkage which separates the lateral intercellular contacts between neighbours in the same sheet in the case of cementoblasts and osteoblasts, but not those between odontoblasts. These differences are considered to be of functional significance and need to be taken into consideration when formulating theories of calcium influx into the mineralizable matrix of the respective tissues.
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    Cell & tissue research 191 (1978), S. 513-523 
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nerve terminals in the palisade zone of the rat median eminence were investigated with freeze-fracture electron microscopy. Fracture face P of the specific terminals showed two populations of intramembranous particles (IMP): a large and a small variety. The large IMP-s often formed small irregular clusters. In nerve terminals the total number of both populations of IMP-s was considerably less than that found on P membrane faces of ependymal feet. On fracture face E of the nerve terminals, the number of IMP-s was about a quarter of that seen on fracture face P. On both fracture faces of most terminals a few small round impressions (or elevations respectively) were found which may be interpreted as broken necks of either exo- or endocytotic vesicles. Neither gap nor tight junctions occurred at lateral membranes of the specific axon terminals. Similarly, no membrane specializations were observed with freeze-fracturing on membrane areas adjacent to the basement membrane. The findings are discussed in relation to a possible exocytosis mechanism of the hypothalamic releasing and inhibiting hormones.
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  • 83
    ISSN: 1432-0878
    Keywords: Taste buds ; Circumvallate papillae ; Colchicine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It is believed that differentiation and maintenance of taste buds in vertebrates is dependent on the trophic function of their sensory nerve supply. In the present work colchicine was injected into the circumvallate papilla of the rat. This produced a reversible blockade of neuroplasmic transport and disappearance of taste buds. Colchicine inhibited the further differentiation of bud cells, but apparently did not change the life cycle of the cells present already at the time of injection. It is speculated that the neurotrophic factors in this particular cell system are effective to induce cell differentiation only.
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    Cell & tissue research 188 (1978), S. 345-359 
    ISSN: 1432-0878
    Keywords: Hippocampal subfields ; Rat ; Volumes ; Timm stain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The absolute volumes of the hippocampal and subicular cortical layers in the rat were determined. The boundaries of the various layers were defined on series of sections made through the entire hippocampal region of five rats and stained according to the Timm sulfide silver technique. Coordinates representing the boundaries of the layers on selected sections were fed into a mini-computer programmed to calculate the volume of the layers from the areas of the profiles and the distances between the sections. The distribution of the layers indicates that they constitute the same proportion of the volume of the dorsal and ventral divisions of the hippocampal region, with the exception of the structures lying in regio inferior and regio superior. Although the combined regio superior and regio inferior components of the layers of Ammon's horn occupy the same percentage of the volume of the dorsal and ventral hippocampal regions, the regio superior components occupy a larger percentage of Ammon's horn in the dorsal region than they do in the ventral region. The inter-animal variations in the volumes of the various layers indicate that it is possible to describe quantitatively the subdivisions of the hippocampal region with a precision that is compatible with comparative studies.
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  • 85
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    Cell & tissue research 188 (1978), S. 491-496 
    ISSN: 1432-0878
    Keywords: Castration ; LH-cells ; Rat ; Development ; Sex-steroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of sex-steroids on the LH-cell development in neonatal rats were studied. The cells were stained immunohistochemically by applying anti-HCG serum. On the second day after birth some of the animals of both sexes were gonadectomized and simultaneously injected with testosterone or estradiol (50 or 200 μg). The remaining animals were either gonadectomized or injected with either one of the sex-steroids. The LH-cell numbers in each group were determined on the 12th day of age from serially cut histological sections of the pituitary. In castrated males the number of LH-cells was about twice that of the intact animals. In the so-called sex-zone, LH-cells tended to be hypertrophied in castrates. These alterations in the appearance of LH-cells did not occur after ovariectomy. In gonadectomized animals injected with sexsteroids (200 μg), the cells were markedly reduced in number and size, both in males and females. Testosterone injection (50 μg) into intact newborn animals also suppressed the numerical development of LH-cells, especially in females. These alterations were particularly evident in the sex-zone in both sexes. Thus the present findings show that sex-steroids may be involved in sexual differences in morphological development of LH-cells in newborn rats.
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  • 86
    ISSN: 1432-0878
    Keywords: Adrenal gland ; Rat ; Vinblastine ; Corticosterone ; Exocytosis
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    Topics: Biology , Medicine
    Notes: Summary Vinblastine treatment blocks corticosterone release from rat adrenal zona fasciculata without impairing hormone synthesis, and induces the formation of acid phosphatase-positive granular clumps at the juxta-sinusoidal pole of the cells. Autoradiography shows that ACTH administration to vinblastine-treated animals mobilizes the 3H-cholesterol stored in the lipid droplets and leads to a noticeable labelling of the granular clumps. The possible significance of these granules is discussed.
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  • 87
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    Cell & tissue research 188 (1978), S. 285-297 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Rat ; Organ culture ; Indole metabolism ; Ultrastructural morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In vitro indole metabolism and ultrastructural morphology of the pineal gland of male rats were examined. A comparison of the effect of norepinephrine stimulation on indole synthesis in whole cultured glands and preparations of dispersed pineal cells is discussed. Our studies on the performance of dispersed cells during the first 24 h after preparation indicate a strong dependence of pineal cells upon physical attachment to the culture dish and probably also on cell-to-cell contact.
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  • 88
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    Cell & tissue research 192 (1978), S. 285-297 
    ISSN: 1432-0878
    Keywords: Intestinal epithelium ; Rat ; Kinetics ; Autonomic denervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of autonomic denervation upon the kinetics of the ileal epithelium of rats was studied by tracing 3H-thymidine labelled nuclei and counting mitotic figures and goblet cells. Counts of labelled nuclei and goblet cells provided information about cell migration along the intestinal epithelium. The mitotic index and turnover time of this population were calculated from the mitotic figures counts. Comparing denervated animals with sham operated controls, it was possible to conclude that autonomic denervation, either sympathectomy or parasympathectomy results in a decrease in mitotic activity. As a result of lower mitotic activity in the crypts, the turnover time increases and there is a delay in the migration of cells from the crypts towards the villi. Sympathectomy causes an early short-lived effect upon the kinetics of the crypt cell population, since after 27 h there is a tendency to normality. Parasympathectomy produces a slower but continuous decline in mitotic activity.
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  • 89
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    Cell & tissue research 190 (1978), S. 61-68 
    ISSN: 1432-0878
    Keywords: Oogonia and M-prospermatogonia ; Rat ; Duration of the S-phase and the minimal generation time ; Comparative autoradiographic studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Bei der Ratte tritt die letzte Generation der Oogonien und “multiplying prospermatogonia” (M-prospermatogonia), die häufig in Form synchronisierter “Cluster” angeordnet sind, um den Tag 17 post conceptionem (p.c.), in die Mitose. Die S-Phasen-Dauer D-S-Duration und die minimale Generationszeit T min der weiblichen und männlichen “Gonien” wurden nach der Methode der markierten Mitosen bestimmt (22 weibliche und 22 männliche Feten von 11 Muttertieren wurden 2–22 Std nach einmaliger i.p. Injektion mit 3H-thymidin getötet). Die drei Kurven markierter Prophasen, Metaphasen und der postmitotischen Abkömmlinge, d.h. der Postmitosephasen der Oocyten und primary transitional prospermatogonia” (T1-prospermatogonia), wurden ausgewertet. Die Auswertungen ergaben, daß der Verlauf der einander entsprechenden Markierungskurven von Prophasen, Metaphasen und Postmitosephasen sowie die daraus errechneten Werte für D-S-Duration und Tmin weitgehend übereinstimmen. Die gewonnenen Werte liegen zwischen 10 und 12,5h für D-S-Duration (10h entsprechend dem Verlauf der markierten Metaphasenkurven) und 16,5 und 18h für Tmin (16,5h entsprechend dem Verlauf der markierten Metaphasenkurven).
    Notes: Summary In the rat the last generation of oogonia and multiplying prospermatogonia (M-prospermatogonia), frequently arranged in synchronized clusters, enters mitosis on about day 17 post conception (p.c.). The duration of the S-phase D-S-Duration and the minimal generation time T min of both kinds of “gonia” were determined by the method of labeled mitoses (22 female and 22 male fetuses derived from 11 pregnant rats were sacrificed from 2 to 22 h after a single i.p. injection of 3H-thymidine on day 17 p.c.). Three curves, derived from the labeled prophases, metaphases and the postmitotic descendents of oogonia and M-prospermatogonia — oocytes and primary transitional prospermatogonia (T1-prospermatogonia) — were evaluated. It was demonstrated that the curves as well as the calculated values of D-S-Duration and T min are very similar for oogonia and M-prospermatogonia. D-S-Duration ranged from about 10 to 12.5 h (10 h read off from the curves of labeled metaphases), T min from 16.5 to 18 h (16.5 h read off from the curves of labeled metaphases).
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  • 90
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    Keywords: Nucl. n. facialis ; Rat ; Retrograde reaction ; Ontogenesis ; Morphometry
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    Topics: Biology , Medicine
    Notes: Summary The grey level index (= GLI) and the fresh volume were determined with the image analyser Micro-Videomat for the nucl. n. facialis after axotomy of the left n. facialis. The experiments were performed on 10 rats in different stages of ontogenesis. The GLI is a quantitative parameter which could be quickly obtained and which demonstrated quantitative changes during retrograde reaction in the respective centres. A decrease in the fresh volumes of the affected nucl. n. facialis could also be demonstrated. The meaning of GLI is discussed.
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  • 91
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    Cell & tissue research 190 (1978), S. 349-355 
    ISSN: 1432-0878
    Keywords: Pineal gland ; Striated musculature ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In a total of 96 rat pineals studied 31 were found to contain striated muscle fibers or their precursors. The muscle fibers were most frequently present in the stalk region and more frequently found in the left than in the right hemisphere. Size measurements revealed that the lengths of pineal muscle cell nuclei differ only slightly from those of the sphincter muscle of the iris. However, the yellowish appearance of pineal muscle cell nuclei under darkfield investigation, a phenomenon observed in all muscular tissues of mesenchymal origin and connective tissue cells, may support the hypothesis that pineal musculature is of mesenchymal rather than ectodermal origin.
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  • 92
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    Cell & tissue research 193 (1978), S. 315-322 
    ISSN: 1432-0878
    Keywords: Intranuclear inclusions ; Pericytes ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This paper deals with the ultrastructure of two types of intranuclear inclusions, “nuclear bodies” and “membranous lamellar bodies”, present in hypothalamic pericytes of intact adult rats. The nuclear bodies exhibited “simple” and “granular” forms, whereas the membranous lamellar bodies were entirely made up of myelin-like membrane whorls. The occurrence of these bodies in nuclei of pericytes has never been previously reported. The origin and functional meaning of such structures is discussed in the light of recent ultrastructural and biochemical studies on nuclear inclusions.
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  • 93
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    Cell & tissue research 194 (1978), S. 163-170 
    ISSN: 1432-0878
    Keywords: Cell kinetics ; Enamel organ ; Cell production ; Cell cycle ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The inner enamel epithelium (IEE) covers the labial tooth aspect as a one cell layer which, when cut sagittally, appears as a longitudinal cell column extending from the tooth origin toward the periphery. Following sudden tooth shortening, the IEE responds by an increased cell production which later declines below normal values. The perturbation affects all cell kinetic parameters; the progenitor compartment, which initially increases, diminishes in size toward end of the experiment. The cell cycle transition times, which initially decline, rise toward the end of the experiment. The mean normal daily cell production rate of 70 cell % (i.e. 70 cells are produced by 100 progenitors) increases to 111 cell % and then declines to a low of 51 cell %. The IEE response typifies the behavior of other cell renewal systems such as intestinal epithelium and epidermis.
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  • 94
    ISSN: 1432-0878
    Keywords: LHRH neuron ; Tissue culture ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Ontogenetic development of LHRH-containing neurons was studied by fluorescence and enzyme immunohistochemistry in rats. In in vitro studies, the tissues of the septal-chiasmatic and mediobasal hypothalamic areas of fetal rats on day 16.5 or 18.5 of gestation were trypsinized separately for dissociation of the neural cells, and cultured for several days. Immunopositive reaction against LHRH was first detected in nerve cells derived from both areas of the hypothalamus of the fetuses on days 16.5 and 18.5 of gestation, after 8 and 6 days culture, respectively. The cells were small, and seemed to be bipolar in morphology indicating an axon and arborized dendrites. Immunopositive material occurred in the cell soma as well as in the cellular processes. In in vivo studies, immunopositive material, possibly deposited in nerve fibers, appeared first in OVLT and simultaneously in the external layer of the median eminence of fetuses on day 20.5 of gestation. The immunoreactive fibers increased in number in both parts with development, especially after birth in the median eminence. No immunopositive material was detected within any neural cell bodies nor in the cytoplasm of any ependymal cells.
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  • 95
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    Cell & tissue research 195 (1978), S. 499-513 
    ISSN: 1432-0878
    Keywords: Somatostatin neurons ; Hypothalamic, extrahypothalamic distribution ; Immunohistochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using a highly sensitive antibody to somatostatin, its hypothalamic and extrahypothalamic distribution in the rat was re-examined by light microscopic immunohistochemistry (PAP-method). The scattered somatostatin-producing perikarya occur in multiple layers within the subependymal neuropil surrounding the third ventricle. They supply with short-distance projections the following hypothalamic nuclei: 1) preoptic nuclei (especially their suprachiasmatic and medial components), 2) the peripheral zones of the suprachiasmatic nuclei, 3) the ventromedial and 4) arcuate nuclei, and 5) the ventral premammillary nuclei. Furthermore, the following long-distance projections have been observed: In a rostral direction (A1) rostral of the anterior commissure to the lamina terminalis, (A2) to the OVLT, (A3) to the olfactory tubercle, and (A4) rostrally and caudally by-passing the anterior commissure to the dorsal part of the stria terminalis. More caudally, at the retrochiasmatic level an ascending dorso-lateral projection joins the ventral amygdalo-hypothalamic pathway in a reciprocal manner (B1). In addition, a descending ventrolateral tract projects to the optic tract bending dorsal to it in different directions: (C1) medial to the median eminence, (C2) lateral to the corticomedial amygdala, and (C3) caudal for additional support of the arcuate and ventral premammillary nuclei. The principal tract of somatostatin-containing fibers descends in the subependymal neuropil to the median eminence (D). The results are discussed with reference to a possible participation of the somatostatin fiber system in the afferent branch of the circuit connecting the hypothalamus with the amygdala via the stria terminalis.
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  • 96
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    Cell & tissue research 190 (1978), S. 181-185 
    ISSN: 1432-0878
    Keywords: Vitamin A ; Ultimobranchial tissue ; Ultimobranchial cysts ; Thyroid ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultimobranchial cysts in the thyroid glands of rats receiving a diet adequate in vitamin A are lined with stratified squamous epithelium and contain non-keratinized cellular debris. The epithelium of these cysts in vitamin A deficient animals is keratinized, and their lumina contain keratinized cellular strands surrounding a core of cellular debris. Upon return to a diet adequate in vitamin A the epithelium returns to a non-keratinized state, and the lumina contain keratinized strands surrounded by cell fragments and desquamated whole cells. Occasionally these cysts have an epithelium that is highly irregular in appearance. The relationship of alterations in this tisssue to possible subsequent development of neoplasias is discussed.
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  • 97
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    Cell & tissue research 191 (1978), S. 183-186 
    ISSN: 1432-0878
    Keywords: Amygdaloid body ; Hypothalamus ; Midbrain ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light microscopic autoradiography was performed subsequent to injection of tritiated amino acids into various parts of the amygdaloid body of the rat. Evidence is provided for two hitherto unreported projections of the amygdala: from the medial amygdaloid nucleus to the contralateral premamillary nuclei and from the central amygdaloid nucleus to the mesencephalic central grey. The functional implications of these findings are discussed.
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  • 98
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    Keywords: Taste bud ; Vallate papilla ; Regeneration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The regeneration of the vallate papilla in the rat was studied by both light and electron microscopy. The papillae were excised and regeneration was studied at time intervals of 3 to 45 days. It was found that the vallate papilla is capable of regeneration after both partial and total papillectomies. The regenerated papillae were asymmetrical in shape. Several invaginations, independent of one another, were the equivalent of the original sulcus. Regeneration of the gustatory system occurred at circumscribed portions of the associated Von Ebner glands. The amounts of newly formed taste buds were proportional to the amount of nerve fibers in the subepithelial plexus. The regenerated taste buds showed normal histochemical and fine-structural characteristics. The results support the contention of some degree of specificity concerning the epithelium where taste bud regeneration occurs.
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  • 99
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    Cell & tissue research 193 (1978), S. 525-532 
    ISSN: 1432-0878
    Keywords: Intranuclear inclusions ; Neurons ; Development ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of intranuclear rodlets, microtubules, fibrillar lattices and membranous inclusions found in the developing cuneate nuclei of rats is described. Rodlets, ranging in diameter from 96–312 nm and in length from 1–2 μm, are made up of tightly packed straight filaments measuring 5–8 nm in diameter. Microtubules with a diameter of 26 nm are clustered together. Fibrillar lattices are made up of fibrils with a diameter of 9 nm arranged in layers or sets. Two to nine sets make up a lattice, with a maximum width of 68 nm, in which the adjacent sets are arranged at an angle to each other. Rodlets and fibrillar lattices occur in 6.8% of the neurons. Membranous inclusions, reported here for the first time in normal neurons, are of 2 types: small vesicles of 0.1–0.6 μm and large vacuoles measuring 1–2 μm. Both types are bounded by either a single or a double membrane and generally have an electron lucent content. Membranous inclusions occur in 25.3 % of the neurons. Changes in the frequency of occurrence of the various intranuclear inclusions in the course of postnatal development are also reported.
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  • 100
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    Cell & tissue research 194 (1978), S. 17-35 
    ISSN: 1432-0878
    Keywords: Synapses ; Optic nerve ; Suprachiasmatic nucleus ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synapses of optic nerve afferents (optic synapses) in the rat suprachiasmatic nucleus (SCN) have been identified ultrastructurally. They are easily distinguished from other types of synapses. The optic boutons are characterized by the presence of large mitochondria with a swollen electron lucent matrix and an interconnected tubular system formed by their inner membrane. Other, more variable features include: 1) a scattered pattern of synaptic vesicles which are found throughout the entire presynaptic element with relatively little accumulation near the active zones; 2) the occurrence of dense core vesicles and glycogen granules; 3) the active zones, the majority of which is Gray-type I, but a minority can obviously be classified as Gray's type II; 4) the innervation of smaller peripheral dendrites and dendritic spines. Boutons of this kind are exclusively filled with anterogradely transported horseradish peroxidase injected into both eyes. Very few neuronal elements containing the typical mitochondria have been observed in the SCN on the 6th day post partum, increasingly more on the 9th and 12th day, but considerably higher numbers after opening of the eyes on the 17th and the following days. The location of normal and degenerating optic boutons was examined light- and electron microscopically. In the rostral third of the SCN there are relatively few optic synapses which are found close to the optic chiasma. In the middle portion of the SCN optic synapses increase in number; they are found not only in the ventral part of the nucleus but also in lateral regions. This becomes particularly obvious in the caudal third of the SCN.
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