Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 53 (1975), S. 559-569 
    ISSN: 1432-1440
    Keywords: Renin ; Angiotensm ; Radioimmunoassay ; Standardisierung der Plasma-Renin-Messung ; Normalwerte der Plasma-Renin-Konzentration beim Menschen ; Renin ; angiotensin ; radioimmunoassay ; standardization of plasma renin measurement ; normal values of human plasma renin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A new method for the measurement of renin in human plasma is described. The method is based on the introduction of the internationally available renin standard of the Medical Research Council (MRC) London, as a calibration system. Thus, some principal disadvantages of methods expressing results in renin reaction velocity (angiotensin generation rate) only are avoided. Both renins, unknown and standard, react with a sheep substrate preparation and are handled identically throughout the whole procedure including the angiotensin I radioimmunoassay (RIA). The plasma renin concentration (PRC) is given in 10−6 MRC-renin units (µU/ml). Results: the renin standard is free of angiotensin, angiotensinases, and angiotensinogen; it is stable on storage. Identical enzyme kinetics are shown for both renins. An interference between endogenous and exogenous substrate could be avoided. The potentially harmful influences of proteins from the enzyme incubation mixture on the RIA dose response curve are shown. The use of an angiotensin I calibration system could be omitted. Using a standard renin dilution from 250–0.9 µU/ml almost the full biological range is covered. When giving an unrestricted diet the preliminary normal values of PRC are 21.9±12.6 µU/ml in recumbent and 40.1±18.8 µU/ml in upright position (n=16,x±s, age 20–35 years). Earlier findings of age-dependancy of PRC were confirmed.
    Notes: Zusammenfassung Es wird eine neue Methode zur Messung von Renin in menschlichem Plasma beschrieben. Die Methode basiert auf der Einführung des Renin-Standards des Medical Research Council (MRC), London als Eichsystem und vermeidet damit die prinzipiellen Nachteile von Verfahren, die Renin nur als Angiotensinbildungsgeschwindigkeit erfassen. Prinzip der Methode ist es, Standard- und Plasma-Renin während der Enzymreaktion (mit Schafsubstrat) und während des Angiotensin I-Radioimmunoassays (RIA) identisch zu behandeln. Die Plasma-Renin-Konzentration (PRC) wird in 10−6 MRC-Renineinheiten (µU/ml) angegeben. Ergebnisse: Der Renin-Standard ist stabil und frei von Angiotensin, Angiotensinasen und Angiotensinogen. Er zeigt gleiche Enzymcharakteristika wie Plasma-Renin. Eine Interferenz von endo- und exogenem Substrat konnte vermieden werden. Mögliche, gravierende Störungen des RIA durch Proteine der Enzymreaktionsansätze wurden nachgewiesen. Eine Eichung über einen Angiotensin I-Standard kann vermieden werden. Bei Anwendung einer Standard-Renin-Verdünnung von 0,9–250 µU/ml wird nahezu der gesamte biologische Bereich erfaßt. Unter freier Kost betrugen die vorläufigen Normalwerte für 30–35jährige in Ruhe 21,9±12,6 µU/ml, nach Orthostase 40,1±18,8 µU/ml (x±s,n=16). Frühere Beobachtungen über eine Altersabhängigkeit der PRC wurden bestätigt.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1440
    Keywords: Plasma renin activity ; Angiotensin II ; Cardiac edema ; Furosemide ; Regulation of sodium balance ; Plasma-Renin-Aktivität ; Angiotensin II ; kardiale Hydropsie ; Furosemid ; Regulation des Naturiumhaushaltes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 8 Gesunden und 21 Kranken mit kardialer Insuffizienz wurden Renin-Aktivität (PRA) und Angiotensin II-Konzentration (A II) im Plasma, Serumnatrium und -kalium und renale Na+-, K+- und Flüssigkeitsexkretion vor sowie 2, 4 und 6 Std nach i.v. Gabe von 0,3 mg Furosemid/kg untersucht. Die PRA wurde biologisch, A II radioimmunologisch bestimmt. Die Gesunden reagierten mit signifikanten Anstiegen der PRA- und A II-Werte (P〈0,005), die Kranken mit kardialer Insuffizienz zeigten 3 verschiedene Verhaltensmuster der PRA: Absinken unter den Ruhewert (4 Fälle), Anstieg (4 Fälle) und Gleichbleiben (14 Fälle, davon 11 ohne meßbare PRA). Eine mangelhafte Stimulierbarkeit der PRA ist somit auch bei kardialer Hydropsie möglich. Die Pat. mit abfallender bzw. gleichbleibender PRA waren vornehmlich Schwerkranke mit ausgeprägter Hydropsie; sie wiesen nach Furosemid im Mittel gleich große, im einzelnen z.T. weit höhere Na+-Verluste auf als die Gesunden. Dies könnte durch die Annahme eines (zentralnervösen) Systems erklärt werden, das die renale Na+-Verlustrate in Beziehung zum Na+-Gesamtbestand setzt und erst ab einer kritischen Relation gegenregulatorisch die Steigerung der Reninfreisetzung veranlaßt. Diese Vermutung wurde durch Untersuchung einer Patientin vor und nach Ödemausschwemmung wahrscheinlich gemacht. PRA- und A II-Werte verhielten sich konkordant (r=+0,627,P〈0,001).
    Notes: Summary In 21 patients with congestive heart failure and 8 normal controls plasma renin activity (PRA), angiotensin II (A II), sodium and potassium concentrations in plasma and renal Na+, K+, and water excretion were measured before and 2, 4, and 6 hours after an intravenous injection of Furosemide (0.3 mg/kg). PRA was determined biologically, A II by radioimmunoassay. The control group showed a significant increase of PRA and A II levels (P〈0.005). In patients with congestive heart failure, three different patterns of PRA were observed: decrease (4 cases), increase (4 cases) and no change (14 cases which comprise 11 patients without detectable PRA), compared to the individual control value. Thus, inadequate stimulation of PRA may occur in congestive heart failure, too. Particularly the patients with decreasing or unchanged PRA suffered from severe cardiac insufficiency with severe edema. After application of Furosemide, these patients showed in average the same, some of them a much higher Na+ loss than the controls. These results could be explained by the assumption of the presence of a control mechanism, possibly located in the brain, that detects the renal Na+ excretion in relation to the total body Na+ and induces the counterregulatory renin secretion not unless a certain reference value is attained. This hypothesis was supported by the results obtained in the same patient before and after loss of edema. PRA and A II values were concordant (r=+0.627,P〈0.001).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-1440
    Keywords: Plasma renin concentration in humans ; micromethod for plasma renin ; sheep angiotensinogen ; plasma renin concentration in babies ; Plasma-Renin-Konzentration beim Menschen ; Mikromethode zur Plasma-Renin-Bestimmung ; Schaf-Angiotensinogen ; Plasma-Renin-Konzentration bei Säuglingen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird ein einfaches, empfindliches Verfahren zur Bestimmung der Plasma-Renin-Konzentration beim Menschen beshrieben, das auf der von Boucheret al. [Canad. J. Physiol. Pharmacol.45, 881 (1967)] angegebenen Methode beruht. 1,0 ml Plasma, 1.0 ml Dowex 50WX2-(NH4)+ und Schaf-Angiotensinogen im Überschuß — gelöst in 2,0 ml EDTA- und NaN2-haltigem Trisphosphatpuffer — werden 15 Std bei 37°C inkubiert. Die Umsetzung des Human-Renins mit dem Schafsubstrat folgte einer Michaelis-Menten-Kinetik und ergab eine 1,5–2fach höhere Angiotensinausbeute als bei der entsprechenden Reaktion mit homologem Substrat. Die Präzision bei Doppelbestimmungen betrug 7,0±6,2% des kleineren Wertes. Die Angiotensin II-Wiederfindungsrate war in dem untersuchten Bereich von 25–200 ng linear und betrug im Mittel 84,4±10%. Bei gesunden Erwachsenen unter freier Kochsalzzufuhr wurde folgender Normbereich ermittelt: 0,9±0,6 ng Angiotensin/ml/h in Ruhe bzw. 2,1±1,0 ng/ml/h nach aktiver Orthostase. Bei gesunden Säuglingen betrug die Plasma-Renin-Konzentration unter ambulanten Bedingungen 3,4±1,6 ng/ml/h und war damit signifikant höher als die Normalwerte der Erwachsenen in Ruhe und nach Orthostase (P〈0,001).
    Notes: Summary A simple, sensitive method for determination of human plasma renin concentration is described. The procedure is based on the method of Boucheret al. [Canad. J. Physiol. Pharmacol.45, 881 (1967)]. One ml plasma and 1.0 ml Dowex 50WX2-(NH4)+ are incubated for 15 hours at 37°C with 150 mg sheep angiotensinogen in 2.0 ml trisphosphate buffer containing EDTA and NaN3. The reaction of the human renin with the sheep angiotensinogen followed the Michaelis-Menten kinetics and yielded a 1.5 to 2 fold amount of angiotensin compared to the reaction with homologous substrate; the recovery of angiotensin was 84.4±10% being linear in the range studied (25–200 ng angiotensin II). The normal values of 22 healthy adults during a free diet were 0.9±0.6 ng angiotensin/ml/h in recumbent and 2.1±1.0 ng/ml/h in upright posture. During ambulatory conditions the plasma renin concentration in healthy babies was 3.4±1.6 ng/ml/h. These values were significantly higher than those in adults in recumbent and upright posture (p〈0.001).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 16 (1978), S. 239-246 
    ISSN: 1432-0630
    Keywords: 72.40 ; 73
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Indium oxide films doped with tin (ITO-films) have been hf-sputtered from an 80 at-%In2O3/20 at-%SnO2 target onto glass substrates. The sputter atmosphere contained mainly argon (10−2Torr) with addition of oxygen (0≦p O 2≦2·10−2Torr). The sputtered films aren-conductors. The conductivity and density of charge carriers depend on the oxygen content of the sputter gas. They could be varied by two orders of magnitude. In air or in oxygen atmosphere the films oxidize at the surface and for a certain depth beneath the surface, thus decreasing the conductivity. The Hall mobility of the sputtered films is smaller (≈10 cm2V−1 s−1) than one observes at ITO films produced by CVD sparaying or other methods. The conductivity of as sputtered films approached maximum values of about 1000Ώ−1cm−1.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-1106
    Keywords: Retina ; Receptive field ; Temporal summation ; Ganglion cell ; Time constant ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Mit Hilfe der Schewellensummation für Reize wachsender Dauer und mit zwei zeitlich getrennten Reizen wurde die Impulsreaktionsfunktion retinaler Ganglienzellen gemessen. Bei einer Reizgröße von 15′ Durchmesser und einer Hintergrundsbeleuchtung von 0.5 asb ergibt eine Exponentialfunktion eine gute Über-einstimmung mit den Meßwerten. Alle Neurone folgten dem Bloch-Gesetz (Is · T = const.) für kurze Reize mit einem kontinuierlichen ×bergang zu einer konstanten Schwelle. 2. Die einzelnen Zeitkonstanten wurden den jeweiligen Schwellensummations-kurven entnommen. Die mittlere Zeitkonstant beträgt 75 ms für On-Zentrum-Neurone und 126 ms für Off-Zentrum-Neurone. Das D-System der Off-Zentrum-Neurone ist gegenüber kurzen gegenüber langen Reizen unempfindlicher als das B-System der On-Zentrum-Neurone. 3. Kurze und lange Zeitkonstanten wurden sowohl in der zentralen als such in der peripheren Retina gedunden, kurze jedoch häufiger bei großer Exzentizität. 4. Die auf die Hintergrundsbeleuchtung begozene Zentrumsempfindlichkeit für kurze Reize ist vereinbar mit einer Schwellenerregung, die im Mittel für alle rezeptiven Felder als gleich groß angesehen werden kann. 5. Das der äumlichen Summation analoge Zeitsummationsverhalten führt zu dem Konzept eines zeitlichen rezeptiven Feldes.
    Notes: Summary 1. The impulse-response function of the retina was estimated at the ganglion cell level by comparing the temporal summation curve with the corresponding time integral. With a test spot of 15′ in diameter and at a background luminance of 0.5 asb, an exponential function with different time constants was found to be a good approximation. All neurons followed Bloch's law, Is · T = c, at short stimulus durations. With increasing stimulus durations, luminance threshold approached a constant. 2. The time constant for each receptive field was taken from the corresponding threshold summation curve. The mean value for on-center fields was 75 ms and for off-center fields 126 ms. The D-system was less sensitive than the B-system. 3. Short time constants were found primarily within a radius of 20° from the area centralis, whereas long time constants were obtained predominantly in the outer periphery. 4. The sensitivity of receptive field centers at short stimulus durations is consistent with an invariant threshold excitation, defined by the dimensionless value of the excitability integral. 5. Spatial and temporal summation are described by the concept of spatiotemporal receptive fields.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 24 (1977), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Electron microscope observations on Thelohania sp. in the shrimp Pandalus jordani support the view that the Golgi complex in Microsporida is a “classical” one, composed of vesicular, vacuolar, and cisternal components. During development of the sporoblast, a portion of the Golgi complex is seen as an electron-dense reticulum enmeshing the core of the polar filament. Associated with the reticulum are electron-dense bodies. The reticulum and “dense bodies,” reported in several previous publications, have not been well understood and have been given a variety of names. The evidence favors the view that these structures have secretory activity in which the reticulum concentrates or synthesizes material, some of which takes the form of membrane-bounded granules. It is suggested that the most appropriate name for the reticulum is “reticulum golgien,” and that the correct name for the “dense bodies” is the standard cytologic term, “secretion granules.” The secretion granules apparently remain in the posterior part of the spore, and may be stored there for some as yet undetermined use.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 228 (1970), S. 358-359 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] It has recently been reported11-13 that cells of people with the hereditary disease, xeroderma pigmentosum, have a low capacity for DKA repair replication14'15 and do not excise the ultraviolet -induced pyrimidine dimers16'17. These patients are very sensitive to ultraviolet light and exhibit a ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 35 (1979), S. 1285-1287 
    ISSN: 1600-5740
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 28 (1972), S. 1489-1490 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung Die Plasma-Renin-Konzentration (PRC) Neugeborener ist höher als die ihrer Mütter, verdoppelt sich innerhalb 48 h und sinkt bis zum 10. Tag unter den Geburtswert. Die PRC der Mütter ist bei der Entbindung sowie am 6. Tag post partum trotz Absinkens auf 50% des Ausgangswertes höher als bei nicht-graviden Kontrollen.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 16 (1978), S. 381-390 
    ISSN: 1432-0630
    Keywords: 73 ; 72.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Indium-tin-oxide films (ITO films) sputtered in Ar-atmosphere with and without addition of oxygen reveal an irreversible increase in conductivity during annealing in vacuum. This annealing process increases drastically the density of free electrons, while the Hall mobility changes only slightly. Below the annealing temperature the temperature dependence of the conductivity is reversible. In films with low density of free electrons, which behave like non-degenerated semiconductors, two activation energies for the mobility could be found. The irreversible changes, observed during annealing in the vacuum, are explained by diffusion of oxygen from the interior of the film to the surface, followed by desorption of the oxygen from the surface into the vacuum. The excess oxygen in the non-stoichiometric films plays the role of electron traps. The irreversible effects during annealing in the vacuum are partly reversible in the long run. If the annealed films are exposed to oxygen or air their conductivity decreases because of diffusion of oxygen from the surface into the film.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...