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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Annals of hematology 38 (1979), S. 397-406 
    ISSN: 1432-0584
    Keywords: Intestinale Resorption von Eisen und Kobalt ; Interaktion zwischen Eisen und Kobalt ; subzelluläre Verteilung von Eisen und Kobalt ; Intestinal absorption of iron and cobalt ; Interaction between iron and cobalt ; Subcellular distribution of iron and cobalt
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary 1. The absorption kinetic of59Fe-(FeCl3) and60Co-(CoCl2) 10 min after administration of increasing doses (0.5–1,000 nmoles metal) into tied-off duodenal segments of normal and iron-deficient rats shows saturation characteristic for both metals; in iron-deficient rats the absorption of both metals was enhanced. 2. The addition of increasing amounts of cobalt to the59Fe-containing test solutions caused a decrease of the absorption of iron. 3. The study of the time dependence of this interaction in iron-deficient rats revealed, that cobalt inhibits the release of iron from mucosal cells into the blood, whereas the uptake of iron from the lumen into the mucosal cells did not differ from the controls without administration of cobalt. 4. The subcellular distribution of59Fe and60Co in mucosal cell homogenates of iron-deficient rats after ultracentrifugation on a polyvinylpyrrolidone-CsCl solution shows a similar pattern for both metals; in the presence of cobalt the subcellular distribution of59Fe is not changed. 5. From these results the conclusion is drawn that cobalt inhibits iron absorption not by an interference with iron binding sites on or in the luminal membranes of the mucosal cells but by an interaction with the releasing process at the contraluminal side.
    Notes: Zusammenfassung 1. 10 min nach Verabfolgung steigender Dosen59Fe-(FeCl3) und60Co-(CoCl2) (0,5-1000 nMol Metall) in abgebundene Duodenumschlingen normaler und eisenarmer Ratten zeigt die Resorptionskinetik für beide Metalle Sättigungscharakteristik; bei eisenarmen Ratten war die Resorption beider Metalle gesteigert. 2. Zusätze von Kobalt zu den59Fe-haltigen Testlösungen hemmten die Eisenresorption. 3. Die Untersuchung des zeitlichen Verlaufes dieser Interaktion an eisenarmen Ratten machte deutlich, da\ Kobalt die Abgabe von Eisen an das Blut hemmt; die Eisenaufnahme aus dem Lumen in die Mucosazellen war hingegen nicht betroffen. 4. Die subzelluläre Verteilung von59Fe und60Co in Mucosazellhomogenaten eisenarmer Ratten zeigt nach Ultrazentrifugation auf einer Polyvinylpyrrolidon-CsCl-Lösung ein ähnliches Verteilungsmuster für beide Metalle; in Anwesenheit von Kobalt ist die subzelluläre Verteilung von59Fe nicht geändert. 5. Aus diesen Befunden wird gefolgert, da\ Kobalt die Eisenresorption nicht infolge einer Interaktion mit eisenbindenden Liganden auf oder in der luminalen Membran der Mucosazellen hemmt, sondern da\ es mit Eisen bei der Abgabe aus dem Epithel ans Blut interferiert.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0584
    Keywords: Eisen-Resorption ; Eisen-Retention ; Sättigungskurve der Eisen-Resorption ; Magenentleerungszeit und Eisen-Resorption ; Iron absorption ; Iron retention ; Saturation type curve of iron absorption ; Gastric emptying time and iron absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary 1. The dose dependence of the iron absorption shows a saturation characteristic if iron (0.25–5μmoles Fe/kg body weight) is administered in tied-off intestinal segments of normal and iron-deficient rats. 2. If the iron doses (2.1–570μmoles Fe/kg body weight) are administered by stomach tube only in normal rats a similar dose dependence curve has been obtained as after administration in tied-off intestinal segments. In irondeficient rats the shape of the dose dependence curve is changed and shows no clear-cut saturation characteristic. 3. The differences of these dose dependence curves are discussed with respect to the differences of the methodological conditions. A saturation type kinetic for absorption cannot be expected under all experimental condititions despite of the existence of a transfer system with limited capacity for the transport of iron.
    Notes: Zusammenfassung 1. Die Dosisabhängigkeit der Eisenresorption zeigt Sättigungscharakteristik, wenn Eisen (0,25–5 μMol Fe/kg Körpergewicht) in abgebundene Dünndarmschlingen normaler und eisenarmer Ratten appliziert wird. 2. Wird Eisen (2, l –570 μMol Fe/kg Körpergewicht) dagegen mit der Schlundsonde verabfolgt, so ist nur bei normalen Ratten ein ähnlicher Verlauf der Dosisabhängigkeit zu beobachten wie nach Applikation in abgebundene Dünndarmschlingen. Bei eisenarmen Ratten ist der Verlauf der Dosisabhängigkeit verändert und zeigt keine eindeutige Sättigungscharakteristik. 3. Die Unterschiede im Verlauf der Kurven, die die Eisenresorption in Abhängigkeit von der Dosis beschreiben, werden im Hinblick auf die verschiedenen methodischen Bedingungen diskutiert. Trotz der Tatsache, daß in der Mukosa des Darmes ein Transportsystem für Eisen existiert, ist eine Sättigungskinetik der Resorption nicht unter allen experimentellen Bedingungen zu erwarten.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Insectes sociaux 24 (1977), S. 274-275 
    ISSN: 1420-9098
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1238
    Keywords: Lung edema ; Acute respiratory distress syndrome ; Leukotrienes ; LTB4 ; Omega-oxidation products of LTB4 ; Broncho-alveolar lavage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Leukotriene (LT) generation has been implicated in the pathogenesis of the acure respiratory distress syndrome, ARDS. In the present study, we analysed broncho-alveolar lavage fluids of patients on mechanical ventilation because of ARDS (17 samples taken from 9 patients) or because of cardiogenic edema (8 samples taken from 6 patients) and of healthy volunteers (10 samples from different donors). LTs were separated as methylated and non-methylated compounds using different HPLC procedures, and were identified by chromatographic mobility, on-line UV-spectrum analysis and post HPLC immunoreactivity. In the lavage samples of the healthy volunteers and the patients with cardiogenic edema, no LTs were detected by these technicues (detection limit≃0.1–0.2 ng/ml lavage fluid). By contrast, in 15 out of 17 samples from patients with ARDS LTB4 or its metabolites 20-OH-LTB4 and 20-COOH-LTB4 were detected. The endproduct of omega-oxidation, 20-COOH-LTB4, represented the quantitatively predominant compound, detected in the range of 0.3–2.6ng/ml perfusate. We conclude that the chemotactic agent LTB4 may be involved in the amplification of inflammatory events encountered in ARDS, and that the oxidized metabolites of LTB4 are particularly suitable for monitoring lung leukotriene generation under conditions of neutrophil efflux and oxidative stress.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1432-1920
    Keywords: Transcranial Doppler sonography ; Duplex scanning ; Arterio-venous malformation ; Real-time sonography ; Transcranial color-coded sonography ; MRI
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Transcranial color-coded real-time sonography (TCCS) is a new diagnostic method allowing the non-invasive imaging of parenchymal and vascular structures of the adult brain through the intact skull. A description of the sonographic findings in two patients presenting with a radiologically ascertained arterio-venous malformation is provided. The AVM's can be depicted in the two-dimensional B-mode image as echodense areas interspersed with zones of lower echodensity. Their extension correlated with corresponding MRI images. The color-coded illustration of intravascular flow phenomena allowed the distinct identification of the major afferent feeding vessels, the venous drainage and of the vascular convolution of both AVM's. Information on hemodynamics, as e.g. the blood supply of the angioma by the contralateral internal carotid artery, are obtained by color-coded identification of intravascular flow direction including analysis of the Doppler frequency spectrrum. All findings obtained by TCCS complied with those established by angiography. We conclude, that TCCS is a suitable method for early diagnosis and long term follow up of cerebral AVM's.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-1920
    Keywords: Brain tumours ; Ultrasonography ; Computed tomography ; Stereotactic biopsy ; Transcranial colour-coded real time sonography ; Glloma ; Central nervous system ; Duplex sonography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Transcranial colour-coded real-time sonography (TCCS) was carried out in 25 patients with brain tumours to determine whether this noninvasive method provides additional information about the extent of solid tumour, its differentiation from oedema, and its tissue components. All 25 patients had serial computed tomography (CT)-guided stereotactic biopsies. Comparison of ultrasound, CT and histological findings revealed that the vast majority of contrast enhancing areas on CT were hyperechogenic (32/33; 97%) and contained tumour tissue (29/32; 91%). Hyperechogenic areas always represented solid tumour (23/23 patients), even when CT showed low density non-enhancing lesions. In lestons hypoechogenic on TCCS and low density on CT, histology consistently revealed necrotic tumour (7/7). Biopsies obtained from parenchyma with normal echogenicity revealed tumour in only 3 of 16 speciemens. Despite the high specificity of TCCS in the differentiation of tumour components, its sensitivity to tumour was inferior to that of CT (24/25; 96%). TCCS thus allows noninvasive preoperative identification of tumour tissue and its extent setting.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Archives of gynecology and obstetrics 254 (1993), S. 296-297 
    ISSN: 1432-0711
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Biological cybernetics 26 (1977), S. 41-44 
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract Building of vertical galleries (“runways”) by termites of the species Heterotermes indicola (Wasmann) is suppressed in the interior area of arrangements of plastic containers with equal groups of termites and takes place preferably at the periphery. This reaction is not induced by chemical, vibrational or thermal influences. Shielding separation by plates of glass, plastic foam or various metals demonstrated, that the influence on activity and directional behaviour is caused by fields produced by the termites. They are most probably alternating electric fields. These biofields act together or, if the direction of the gradients differs, in competition with a weak alternating magnetic field in the air-conditioned experimental room. The centrifugal reaction of the termites to the biofields which do not influence the feeding activity, induces gallery building at the periphery of the nesting area.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-0711
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 279 (1976), S. 183-185 
    ISSN: 1618-2650
    Keywords: Schneller Schmelzaufschluß von Oxiden ; induktive Heizung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Eine Methode zur schnellen Durchführung einzelner Schmelzaufschlüsse oxidischer Stoffe wird beschrieben. Durch Steigerung der Temperatur auf 1600° C konnte die Aufschlußdauer auf 2–3 min herabgesetzt werden. Ein speziell hergestellter Pt-Tiegel wird in einen induktiv heizbaren Keramiktiegel eingesetzt. Die erhaltene Schmelze ist erheblich dünnflüssiger als bei Temperaturen von 1100° C. Der etwas höhere Materialverlust 1st elementspezifisch und kann korrigiert werden. Boraxaufschlüsse werden als Beispiel beschrieben.
    Notes: Abstract By increasing the temperature to 1600° C the fusion time could be reduced to 2–3 min. A special Pt crucible is inserted into an ceramic crucible which is heated inductively. The melt is of considerably less viscosity than one obtained at 1100° C. The somewhat higher loss in material is element-specific and can be corrected. Borax fusions are given as examples.
    Type of Medium: Electronic Resource
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