Library

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
    Diabetologia 5 (1969), S. 11-21 
    ISSN: 1432-0428
    Keywords: Rat ; experimental diabetes ; hydrochlorothiazide ; N-monomethyl-acetamide ; discrepancy between serum immunoreactive insulin and suppressible insulin-like activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Aucun effet diabétogène ni hyperglycémiant aigu de l'hydrochlorothiazide (HCT) n'a été décelé par des déterminations de la glycémie à jeun (avant et 2–8 h après l'administration d'HCT) et de la tolérance au glucose effectuées chez des rats normaux et des rats sensibilisés à un effet diabétogène par une pancréatectomie subtotale ou par l'injection d'une dose subdiabétogène d'alloxane, au cours d'un traitement de 6 semaines par des doses de 50–200 mg/kg · jour d'HCT p. o. — De fortes doses (plus de 3 ml/kg) de N-monométhylamide de l'acide acétique (NMMAA), solvant qui fut utilisé dans la préparation d'une solution injectable commerciale d'hydrochlorothiazide, ont par contre exercé des effets diabétogènes très marqués chez le rat. Toute dose léthale de NMMAA a induit chez cet animal un syndrome diabétique, c'est-à-dire une hyperglycémie progressive avec aeido-cétose métabolique, ressemblant au syndrome diabétique aigu induit par l'injection d'une forte dose de sérum anti-insulinique. — Des fractions de doses léthales administrées quotidiennement pendant plusieurs jours ont exercé des effets diabétogènes et léthaux cumulatifs: la substance ou l'un de ses métabolites toxiques apparaît persister longtemps dans l'organisme du rat.-Des doses subléthales de NMMAA ont induit une hyperglycémie réversible d'une durée de quelques jours. Nous avons donc constaté que le diabète produit par le NMMAA était soit transitoire soit léthal. Aucun signe de toxicité ne s'est manifesté au cours d'un traitement de 6–8 mois par des doses inférieures à 0,5 ml/kg · jour. — Chez les rats intoxiqués par une dose léthale de NMMAA, une corrélation positive très significative a été notée entre les valeurs sériques d'insuline immuno-réactive (IRI) et les valeurs de glycémie. Bien qu'ils aient été, à glycémie comparable, supérieurs à ceux constatés dans le sérum de rats normaux après surcharge de glucose, les taux d'IRI se trouvant dans le sérum des rats intoxiqués n'ont pas été en mesure de s'opposer à l'élévation régulière de la glycémie jusqu'à la mort. — L'effet hypoglycémiant d'insuline cristalline porcine est apparu inhibé chez les rats intoxiqués par le NMMAA, comparé à l'effet observé chez des rats normaux ou en diabète alloxanique.-Utilisant l'augmentation de l'oxydation du premier atome de carbone du glucose-l-C14 par le tissu adipeux épididymaire du rat, in vitro, comme index métabolique de l'activité insulino ïde du sérum (ILA), nous n'avons pas constaté, dans le sérum des rats intoxiqués et en état de forte hyperglycémie, des taux d'ILA significativement supérieurs à ceux présents dans le sérum de rats témoins à jeun. Alors que, chez des rats normaux, la fraction de l'ILA sérique supprimable par sérum anti-insulinique (SILA) s'élevait fortement, comme l'IRI, au cours de l'hyperglycémie induite par une surcharge de glucose, cette fraction SILA n'est pas apparue en quantités décelables dans le sérum des animaux intoxiqués. L'IRI sérique de ces animaux n'a donc semble-t-il pas exercé d'effet «insulin-like» sur le tissu adipeux isolé de rat normal.-Les faits observés amènent à la conclusion que les rats intoxiqués par le NMMAA inactivent et l'insuline endogène et l'insuline exogène. Bien qu'ayant perdu son activité métabolique, l'insuline endogène inactivée reste immunologiquement compétente.
    Abstract: Zusammenfassung Große Dosen von Hydrochlorothiazid (50–200 mg/kg/Tag, oral) über einen Zeitraum von 5–6 Wochen riefen weder eine Steigerung der Nüchternblutzuckerspiegel, noch eine Herabsetzung der Glucosetoleranz bei normalen Ratten oder Ratten hervor, deren Empfindlichkeit gegenüber diabetogenen Substanzen durch eine subtotale Pankreatektomie oder durch subdiabetogene Dosen von Alloxan erhöht worden war. 8 Std. nach einer Einzeldosis von 50 mg/kg Hydroehlorothiazid fand sich keine Blutzuckererhöhung. Dagegen hatten große Dosen (über 3.5 ml/kg) des Lösungsmittels N-Monomethylacetamid (NMMAA), das vorübergehend zur Herstellung eines injizierbaren Hydrochlorothiazidpräparates gedient hat, deutliche diabetogene Effekte bei Ratten. Letale Dosen von NMMAA führten immer zu einem diabetischen Syndrom, d.h. fortschreitende Hyperglykämie mit Ketonämie und metabolischer Acidose, das mit dem diabetischen Syndrom nach Verabreichung großer Mengen von Anti-Insulin Serum große Ähnlichkeit aufwies. Bruchteile der letalen Dosis, die wiederholt an aufeinanderfolgenden Tagen gegeben wurden, summierten sich in ihrer diabetogenen und letalen Wirkung : NMMAA oder seine wirksamen Abbauprodukte scheinen längere Zeit im Organismus zu persistieren. Subletale Dosen von NMMAA lösten eine reversible Blutzuckererhöhung für einige Tage aus. Der durch NMMAA hervorgerufene Diabetes war also entweder reversibel oder tödlich. Die Langzeitbehandlung mit Dosen unter 0.8 ml/kg führte auch nach 6–8 Monaten zu keinerlei toxischen Anzeichen. Bei Ratten, die mit letalen Dosen von NMMAA vergiftet wurden, stiegen die Insulin-und Glucose-Spiegel im Blut gleichsinnig an, wobei das Insulin ähnliche Konzentrationen wie bei normalen Ratten erreichte, bei denen orale oder i.v. Glucosezufuhr zu einer entsprechenden Blutzuckersteigerung geführt hatte.-Das während der NMMAA Hyperglykämie sezernierte Insulin bewirkte also keine Blutzuckersenkung. Im Gegensatz zu der glucoseinduzierten Hyperglykämie bei der normalen Ratte stieg die mit Antiinsulin hemmbare insulinähnliche Aktivität während der NMMAAHyperglykämie nicht auf meßbare Werte an, d.h. das IRI der vergifteten Tiere schien auf normales, isoliertes Fettgewebe keinen insulinähnlichen Effekt auszuüben.-Die blutzuckersenkende Wirkung von exogenem SchweineInsulin war bei mit NMMAA vergifteten Ratten niedriger als bei Normaltieren oder Ratten mit Alloxandiabetes.-Diese Befunde veranlassen zu der Schlußfolgerung, daß mit NMMAA vergiftete Ratten exogenes und endogenes Insulin inaktivieren, wobei das inaktivierte endogene Insulin trotz des Verlustes seiner Stoffwechsel-wirkung immunologisch aktiv bleibt.
    Notes: Summary Large doses of hydrochlorothiazide (50-200mg/kg/day p.o.) given for 5 to 6 weeks did not induce any increase in the fasting blood-sugar concentration, nor any decrease of glucose tolerance in normal rats and in rats “sensitized” toward diabetogenic agents by a subtotal pancreatectomy or by a sub-diabetogenic dose of alloxan. No increase in blood sugar was found in the 8 h following a single oral dose of 50 mg/kg of hydrochlorothiazide. —Large doses (〉 3.5 ml/kg) of the solvent N-monomethyl-acetamide (NMMAA), used at one time in the preparation of one brand of hydrochlorothiazide for injection, on the other hand, exerted marked diabetogenic effects in the rat. Lethal doses of NMMAA always induced a diabetic syndrome, i.e. progressive hyperglycaemia with ketonaemia and metabolic acidosis resembling the diabetic syndrome induced by large doses of antiinsulin serum. Fractions of lethal doses given repeatedly on successive days had additive diabetogenic and lethal effects: the drug or its toxic metabolites appeared to persist for a long time in the organism.-Sublethal doses of NMMAA induced a reversible hyperglycaemia of some days' duration. Thus the diabetes induced by NMMAA was either transitory or lethal. Chronic treatment with doses 〈 0.8 ml/kg/day did not induce any signs of toxicity within 6–8 months. In the rats intoxicated with lethal doses of NMMAA, the serum concentration of immunoreactive insulin (IRI) increased simultaneously with the glycaemia, and attained the same levels as in normal rats with similar blood glucose concentrations established by oral or i.v. loads with glucose.-The insulin secreted during NMMAA hyperglycaemia, thus, did not lower the blood sugar. During NMMAA hyperglycaemia, in contrast to glucose-induced hyperglycaemia in normal rats, the fraction of the insulin-like-activity of the serum suppressed by anti-insulin serum (SILA) did not rise to detectable levels : i. e. the IRI of the intoxicated animals did not appear to exert an insulin-like effect on normal isolated adipose tissue.-The blood-sugar-lowering effect of exogenous porcine insulin was depressed in rats intoxicated with NMMAA in comparison with normal animals or animals with alloxan-induced diabetes.-The findings lead to the conclusion that rats intoxicated with NMMAA inactivate exogenous as well as endogenous insulin. Although losing its metabolic activity, the inactivated endogenous insulin remains immunologically competent.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 129 (1969), S. 41-52 
    ISSN: 1432-0568
    Keywords: Differentiation ; Hypothalamo-hypophyseal system ; Sexual differentiation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ontogenetic development of the hypothalamic nuclei of the rat was examined from the 16th post-coital day to adult age in both sexes, which were determined separately. The following conclusions have been drawn: 1. The hypothalamus is visible already before the 16th day of gestation. 2. The walls of the third ventricle are first composed of primitive cell layers, from which the migration of neurons proceeds on the 15th or 16th day. At this stage the differentiation of the wall of the third ventricle occurs: the germinal-, mantle-and marginal layers appear. 3. The differentiation of the nuclei starts, with some exceptions, before the 19th day of gestation. 4. Nn. suprachiasmaticus, supraopticus, periventricularis anterior, arcuatus and one part of paraventricularis differentiate from the lateral border of the germinal layer. Nn. ventromedialis, dorsomedialis, hypothalamicus anterior, praeoptici, praemamillaris ventralis, praemamillaris dorsalis, mamillaris medialis, mamillaris lateralis and the greater part of paraventricullaris differentiate from the mantle layer. Lateral nuclei, of which only nucleus tuberomamillarius has been described, differentiate from the marginal layer. 5. Some nuclei which belong to the hypothalamo-hypophyseal area have a peak in their differentiation during the critical period when the function of the hypothalamo-hypophyseal axis also starts. 6. It is stated that the development of the nuclei in the rat hypothalamus compared to that of the other mammals is similar only to that of the mouse. It takes place quite slowly before and after birth. 7. Sexual differences are not to be seen in the development of the nuclei.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 9 (1969), S. 63-72 
    ISSN: 1432-1106
    Keywords: Noradrenaline and 5-hydroxytryptamine nerve terminals ; Cortex cerebelli ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The monoamine innervation of the cerebellum of the rat has been studied by both in vivo and in vitro techniques using the histochernical fluorescence method for the demonstration of catecholamines (CA) and certain tryptamines. By way of a pharmacological approach using inter alia protriptyline, which acts mainly by blocking the membrane pump of the noradrenaline (NA) neurons, evidence was obtained that CA nerve terminals in the cerebellum mainly represent NA nerve terminals. These were found to innervate practically all parts of the cerebellar cortex with a patchy innervation pattern and with an innervation of especially the anterior and posterior lobes. The terminals mainly seem to make axodendritic contacts in the molecular and granular layers without any strict localization of the terminal plexus to any special plane of the cerebellar folia. The fibers enter the cerebellum via the inferior cerebellar peduncle and run in the white matter of the cortex cerebelli. Incubation studies with 6-hydroxytryptamine indicate that there exists also a 5-hydroxytryptamine (5-HT) innervation of the cortex cerebelli, although not as pronounced as the NA innervation. The 5-HT nerve terminals are very fine, varicose fibers and innervate mainly the molecular layer, especially of the anterior lobe. The terminals run mainly in the transverse plane of the folium parallel to the surface. Thus, the pattern of innervation of these 5-HT afferents is different from that of the NA nerve terminals. In the uvula, structures which may represent the “rosettes” of the mossy fibers or golgi axon terminals in the granular layer take up and accumulate monoamines after incubation with amine in vitro. The exact nature of these structures remains to be elucidated.The cerebellar nuclei receive a very low to low degree of innervation of NA and 5-HT nerve terminals.
    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
    Clinical and experimental medicine 150 (1969), S. 354-360 
    ISSN: 1591-9528
    Keywords: Chelating agents ; Toxicology ; Intestine ; Rat ; Chelatbildner ; Toxikologie ; Darm ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die s. c. Verabfolgung von Na2 [Ca-ÄDTA] und Na3 [Ca-DTPA] in unterschiedlichen Dosen führt zu einer Degeneration der Mucosa des Dünndarms, wobei sich eine sehr gute quantitative sowie qualitative Korrelation zwischen chelat- bzw. dosisabhängiger Schädigung und Letalität zeigt.
    Notes: Summary Subcutaneous administration of different doses of Na2 [Ca-EDTA] und Na3 [Ca-DTPA] leads to a severe damage of the mucosa of the small intestine. This lesion shows a close qualitative and quantitative relation to the lethal effects of the chelators.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 151 (1969), S. 55-63 
    ISSN: 1591-9528
    Keywords: Postischemic edema ; Protease inhibitor ; Trasylol ; Diminishing effect on edema ; Rat ; Postischämisches Ödem ; Proteinaseninhibitor ; Trasylol ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Intravenöse Trasylolgabe kann die Entwicklung eines postischämischen Ödems in proportionaler Dosisabhängigkeit zwischen 10000 und 35000 KIE pro Kilogramm Körpergewicht hemmen. Die intensivste, gegenüber einer Dosis von 35000 KIE//kg KG aber nicht viel stärkere Hemmwirkung, wird mit 50000 KIE/kg KG bei intravenöser Injektion kurz vor Tourniquet-Lösen erreicht. Gaben bis zu 2 1/2 Stdvor und 1 Stdnach Lösen des Tourniquets zeigen ebenfalls noch einen gewissen Effekt. Eine deutliche Wirkung ist auch dann zu erzielen, wenn Trasylol vor Abschnüren der Extremität gegeben wird. Dabei ist der Wirkungsmechanismus nicht eindeutig. In Frage kommt, daß die Entstehung gefäßaktiver Peptide verhindert wird oder daß Trasylol direkt permeabilitätsmindernd auf die Gefäße wirkt.
    Notes: Summary Intravenous injection of Trasylol can stop the development of postischemic edema in a proportional dose response relationship between 10000 and 35000 KIE per kg body weight. The most intensive effect was seen with 50000 KIE per kg injected just prior to the release of the tourniquet, but this effect was not much stronger than with 35000 KIE. An effect could still be demonstrated when Trasylol was given until 2 1/2 h prior to or 1 h after tourniquet release. A marked effect could be obtained even if Trasylol was given prior to tourniquet application. So far the mode of action is not clear. It might be possible, that the development of vasoactive peptides is hindered or that Trasylol has a direct diminishing effect on the permeability of the vessels.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 151 (1969), S. 64-73 
    ISSN: 1591-9528
    Keywords: Tourniquet-shock ; Kinins ; Postischemic edema ; Protease inhibitor ; Rat ; Tourniquet-Schock ; Kinine ; Postischämisches Ödem ; Proteinaseninhibitor ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Im doppelseitigen Tourniquet-Schock mit vierstündiger Ischämie und 28°C Umgebungstemperatur starben die Kontrolltiere nach rund 2 Std unter Entwicklung eines postischämischen Ödems. Mit dem Proteinaseninhibitor Trasylol konnte sowohl das Ödem vermindert als auch das Überleben verlängert werden. Als günstigste Dosis erwies sich eine Gabe von 25000 KIE/kg kurz vor Tourniquet-Lösen. Danach überlebten von 20 Tieren 13 (65%) die vierfache Zeit von Kontrollen, während sich 7 (35%) völlig erholten. Durch intravenöse Applikation vor Anlegen der Tourniquets konnte zwar die lokale Ödementwicklung gehemmt, die Überlebenszeit aber nicht verbessert werden. Daraus wird auf mindestens zwei Angriffspunkte der Trasylolwirkung geschlossen.
    Notes: Summary In experiments with tourniquet application on both hind legs for 4 h at a temperature of 28°C throughout the experiments the controls succumbed about 2 h after tourniquet release, developing postischemic edema. The development of the edema could be diminished by the protease inhibitor Trasylol as well as the survival time could be prolonged. The optimal effect was seen with the injection of 25000 KIE per kg body-weight i.v. just prior to tourniquet release. In this group of 20 animals 13 (65%) survived four times the time of the controls and 7 (35%) recovered completely. By intravenous injection just prior to the application of the tourniquets the local edema could also be diminished but the survival time could not be prolonged. It is concluded that the Trasylol effect must be brought about by at least two modes of action.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 151 (1969), S. 89-92 
    ISSN: 1591-9528
    Keywords: Hexacyanoferrate(II) ; Thallium ; Rat ; Hexacyanoferrat(II) ; Thallium ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die orale Verabfolgung der kolloidalen Fe(III)-, Co(II)- und Ni(II)-Hexacyanoferrate(II) bewirkt eine starke Herabsetzung der Retention von oral oder intravenös verabreichtem Thallium(I) durch die Organe der Ratte. Die Effektivität ist höher als die des sogenannten unlöslichen Berliner Blau.
    Notes: Summary Oral administration of colloidal Fe(III)-, Co(II)- and Ni(II)-hexaoyanoferrates(II) leads to a markedly diminished retention of orally or intravenously administered thallium(I) by the organs of the rat. The efficacy surpasses that of the so-called insoluble Prussian Blue.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 151 (1969), S. 93-102 
    ISSN: 1591-9528
    Keywords: Rat ; Nephron ; Alkaline Phosphatase ; ATPases ; Quantitative Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary With three phosphohydrolases, i. e. alkaline phosphatase (Na+K+), ATPase and (Mg++) ATPase, a segmentation of the proximal tubule and a marked difference between the short (superficial) and long (Juxtamedullary) nephron is revealed by quantitative histochemistry. With the exception of the superficial nephron of the male rat, alkaline phosphatase activity increases along the proximal tubule independent of sex. (Na+K+) ATPase and (Mg++) ATPase show in both types of nephrons a decrease of activity along the proximal tubule. The juxtamedullary nephron is more active than the superficial. Parallelism of the site of avtivity for alkaline phosphatase and the location of reabsorption of phosphate ions is discussed. Morphological and physiological data from the literature are brought into connexion with the enzymatic changes of a (Na+K+) ATPase activity decrease.
    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
    Clinical and experimental medicine 150 (1969), S. 70-75 
    ISSN: 1591-9528
    Keywords: Nitrogen balance ; Man ; Rat ; Stickstoffbilanz ; Mensch ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Stoffwechselbilanzversuche unter dem Kriterium des minimalen Stickstoffumsatzes bei Bilanzausgleich werden am Menschen wie an der Laboratoriumsratte mit der gleichen analytischen Genauigkeit ausgeführt. Versuche an Ratten haben — im Gegensatz zu früher ermittelten Resultaten an Menschen — ergeben: 1. Der Ersatz von Eiprotein-N durch Ammonium-N führt in jedem Mischungsverhältnis zu einer Erhöhung des Stickstoffumsatzes. 2. Methioninzulagen zu Ei/NH4 +-Gemischen bleiben ohne Einfluß auf die Stickstoffumsatzgröße. 3. Eine allgemeine Möglichkeit zur Übertragung von Ergebnissen der Rattenversuche auf den Bedarf des Menschen an Stickstoffträgern besteht für die Bilanzmethode nicht.
    Notes: Summary Metabolism trials under conditions of minimum nitrogen input and nitrogen equilibrium yield the same analytical accuracy (reproducibility of results within a standard deviation of ±1.5%) with men and with rats. In contrast to results with men published formerly, experiments with rats show the following: 1. Replacement of egg protein by non-essential nitrogen (diammoniumcitrate) in any proportions leads to increased nitrogen requirements. 2. Addition of methionine to mixtures of egg protein and ammonia is of no influence on the dimension of nitrogen requirements. 3. A possibility for deducing men's nitrogen requirements from minimum balance results with rats (or vice versa) thus apparently does not exist.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0738
    Keywords: Ascorbic Acid Excretion ; Hepatic Ascorbic Acid Concentration ; Early Injury ; Carbon Tetrachloride ; Rat ; Ascorbinsäure-Ausscheidung ; Leber-Ascorbinsäure-Konzentration ; Frühschädigung ; Tetrachlorkohlenstoff (CCl4) ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Wirkung von CCl4 auf die Ascorbinsäure-Konzentration in der Leber und die Ascorbinsäure-Ausscheidung mit dem Harn wurde bei erwachsenen Ratten innerhalb der ersten 22 Std nach der Applikation untersucht. In der Frühphase der CCl4-Wirkung kommt es zum Anstieg der Konzentration in der Leber. Der früheste signifikante Anstieg wurde 30 min nach der Applikation beobachtet. Das Maximum wurde dosisabhängig zwischen 90 und 180 min erreicht. Das Anwachsen der Ascorbinsäure-Konzentration in der Leber wird mit einer Aktivitätssteigerung vorhandener an der Ascorbinsäure-Synthese beteiligter Enzyme erklärt. Der Erhöhung der Leber-Ascorbinsäure-Konzentration folgt ein dosisabhängiger Abfall mit einem Minimum 12 Std nach der Applikation, der mit einer gleichfalls dosisabhängigen Erhöhung der Ascorbinsäure-Ausscheidung verbunden ist. Danach kommt es zu einem im zeitlichen Verlauf dosisabhängigen Wiederanstieg der Leber-Ascorbinsäure-Konzentration.
    Notes: Summary The effects of carbon tetrachloride on the concentration of ascorbic acid in the liver and on ascorbic acid excretion in the urine of adult rats were studied over a period of 22 hours after intraperitonal application. During the initial phase of the carbon tetrachloride effect, there results an increase in the concentration of ascorbic acid in the liver. The earliest significant rise was observed 30 minutes after application. The maximal rise came between 90 and 180 minutes, depending on the dose. The increase in the ascorbic acid concentration in the liver is explained by an increase in activity of those enzymes present which participate in ascorbic acid synthesis. The enhancement of hepatic ascorbic acid concentration is followed by a dose-related decrease which reaches a minimum 12 hours after application and which is accompanied by a silmultaneous increase in ascorbic acid excretion. Thereafter in the course of time, there results a renewed dose-dependant increase in the ascorbic acid concentration in liver.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 3 (1969), S. 96-99 
    ISSN: 1432-0827
    Keywords: Calcium metabolism ; Strontium metabolism ; Fracture ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La relation entre la résorption du85Sr et du47Ca était mesuré au tibia et fémur des rats 24 heures après l'injection. La différence entre les manches et les bouts était, remarquable, mais pas entre les os séparates; en les tibiae, qui etait fracturé depuis 7 semaines et guéries, la relation etait identique à celui des tibiae manches normals. On a présumé que la découverte était due à des différences qualitatives plustot que quantitatives entre les procédé de minéralisation dans l'os cortical et trabeculair.
    Abstract: Zusammenfassung Das Verhältnis zwischen der Abnahme von85Sr und47Ca wurde von der Tibia und Femur 24 Std nach der Injektion bei Ratten gemessen. Man fand einen signifikanten Unterschied zwischen den Schaften und den Enden, aber nicht zwischen den verschiedenen Knochen. In 7 Wochen alten, verheilten Tibiafrakturen war das Verhältnis genau so wie in einem normalen Tibiaschaft. Das Resultat berechtigte zu der Annahme, daß der Unterschied in dem Mineralisierungsprozeß zwischen corticalen und spongiösen Knochen wahrscheinlich qualitativ und nicht quantitativ ist.
    Notes: Abstract The ratio between the uptake of85Sr and47Ca was measured in the tibiae and femora of rats 24 h after injection of the tracers. There was a significant difference between shafts and ends but not between the different bones; in healed tibial fractures, 7 weeks old, the ratio was identical to that of normal tibial shafts. The findings were interpreted to be related to qualitative rather than quantitative differences in mineralization between cortical and trabecular bone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 265 (1969), S. 149-155 
    ISSN: 1432-1912
    Keywords: Digitoxose ; Metabolism ; Liver Enzymes ; Excretion ; Rat ; Digitoxose ; Stoffwechsel ; Leberenzyme ; Ausscheidung ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An NAD dependent “digitoxose dehydrogenase” has been demonstrated in extracts from rat liver; the Km values of this enzyme have been determined. Polyacrylamide disc gel electrophoresis shows that there are at least four different proteins capable of oxidizing digitoxose. After i.p. injections of digitoxose into normal rats 53.3% of the deoxysugar injected are excreted in the animals' urine as digitoxose, digitoxonic acid or digitoxonic-γ-lactone. The corresponding figure for adrenalectomized rats instead of normal animals is 68.3%-“Digitoxose dehydrogenase” of the rat liver seems to be a constitutive enzyme. The increased excretion of digitoxonic-lactone following adrenalectomy can be interpreted as a “permissive effect” of the adrenal hormones upon digitoxose metabolism beyond the stage of the digitoxonic lactone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 262 (1969), S. 405-418 
    ISSN: 1432-1912
    Keywords: Chelating Agents ; Isotopic Dilution ; Radioactive Iron ; Rat ; Chelatbildner ; Isotopische Verdünnung ; Radioeisen ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurde der Einfluß verschiedener Chelatbildner auf die Verteilung und Ausscheidung von trägerfreiem und isotopisch verdünntem Radioeisen bei der Ratte untersucht. Während bei gleichzeitiger Verabfolgung der Chelatbildner die Retention in allen Geweben herabgesetzt wird, führt die nachträgliche Verabreichung zu einer nur geringfügigen Mobilisierung von Depoteisen aus Leber und Milz. Die Wirksamkeit ist im Falle von isotopisch verdünntem Radioeisen größer. Äthylendi-(α-o-hydroxyphenyl)glycin, 2-(β-Aminoäthoxy)cyclohexylamintetraacetat und Desferrioxamin B erwiesen sich als die wirksamsten Verbindungen, wobei jedoch die hohe Toxicität der ersteren die praktische Verwendung ausschließt.
    Notes: Summary The influence of various chelating agents on the distribution and excretion of radioiron, carrier-free or diluted with stable carrier, was studied in rats. Simultaneous administration of chelating agents lowers the retention of radioactive iron in all tissues whereas after delayed treatment a small fraction of storage iron can be removed from liver and spleen. The efficacy is higher in the case of isotopically diluted radioactive iron. The most effective compounds are ethylenedi-(α-o-hydroxyphenyl)glycine, 2-(β-aminoethoxy)cyclohexylaminetetraacetate, and desferrioxamine B. The practical value of the former chelator, however, is excluded by its high toxicity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 264 (1969), S. 55-75 
    ISSN: 1432-1912
    Keywords: Intestinal Blood Mow ; Intestinal Absorption ; Drugs ; Jejunum ; Rat ; Darmdurchblutung ; Resorption ; Pharmaka ; Jejunum ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Bei Urethan-narkotisierten Ratten wurde eine Jejunumschlinge mit14C-markierten Arzneimitteln in gepufferter isotonischer Kochsalzlösung mit einem pH von 6–8 (Amidopyrin, Anilin, Antipyrin, Benzoesäure, Salicylsäure) und einem pH von 2,2–3,0 (Amidopyrin, Benzoesäure) perfundiert. 2. Wurde die Durchblutung von etwa 1,5 auf 0,2 ml/min · g Feuchtgewicht gesenkt, dann nahm die Resorptionsrate aller Arzneimittel ab. Wurde umgekehrt die Durchblutung von anfänglich niedrigen Werten auf hohe Werte gesteigert, dann stieg die Resorption der nichtionisierten Arzneimittel in entsprechender Weise an, während die Resorption der ionisierten Arzneimittel nicht beeinflußt wurde. Bei gleichbleibender mittlerer Durchblutung (0,6–0,7 ml/min · g) blieb die Resorptionsrate der nichtionisierten Arzneimittel (mit Ausnahme von Amidopyrin) konstant, während sie bei den ionisierten über einen Zeitraum von 60 min um 15–22% abnahm. 3. Das abweichende Verhalten der ionisierten Arzneimittel gegenüber Durchblutungsänderungen wird auf folgenden Mechanismus zurückgeführt: maßgebend für ihre Resorption ist der leicht saure und von der Perfusionslösung weitgehend unabhängige pH-Wert (virtual pH) in einem Bereich unmittelbar an der Mucosaoberfläche (microclimate). Eine verminderte Mucosadurchblutung führt nicht nur zu einer Verringerung der Dränagewirkung (die alle Pharmaka betrifft), sondern auch zu einer hypoxischen Schädigung des Zottenepithels und einer Anderung des virtuellen pH, die nur die Resorption der ionisierten Arzneimittel beeinträchtigt.
    Notes: Summary 1. Jejunal loops were prepared in anaesthetized rats and perfused with14C-labelled drugs in buffered isotonic saline solutions at pH 6–8 (amidopyrine, aniline, antipyrine, benzoic acid, salicylic acid) and at pH 2.2–3.0 (amidopyrine, benzoic acid). The blood flow in the loops and the absorption rate of the drugs were determined simultaneously. 2. A decrease of the blood flow from about 1.5 to O.2 ml/min X g wet tissue diminished the absorption rate of all drugs, whereas an increase of the blood flow from low to high values caused only an increased absorption rate of the unionized but not of the ionized drugs. When the blood flow was held constant (0.6–0.7 ml/ min X g wet tissue), the absorption rate of the unionized drugs (with the exception of amidopyrine) remained constant, whereas the absorption rate of the ionized drugs decreased by 15–22% within 60 min. 3. The different reaction of the ionized drugs to blood flow alterations is assumed to be due to the following mechanism: the absorption of the ionized drugs is substantially favoured by a “virtual pH” near the mucosal border which is slightly acidic and largely independent of the pH within the gut lumen. A period with insufficient mucosal blood flow results not only in a diminished drainage of the mucosa-which affects the absorption rate of all drugs-, but also in a hypoxic impairment of the epithelium and its capability to maintain the “virtual pH”. This failure affects only the absorption rate of the ionized drugs.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 262 (1969), S. 53-72 
    ISSN: 1432-1912
    Keywords: Cardiac Glycosides ; Intestinal Absorption ; Rat ; Guinea Pig ; Herzglykoside ; enterale Resorption ; Ratte ; Meerschweinchen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Durchtritt und Bindung von 3H-markiertem Ouabain, Digitoxin, Digoxin, Peruvosid und Proscillaridin wurden am isolierten, durchströmten Dünndarm von Ratten und Meerschweinchen in vitro untersucht. 2. Der Durchtritt der Glykoside durch die Darmwand ist proportional der Konzentration. Für die Penetrationsfähigkeit ergibt sich bei der Ratte die Reihenfolge: Digitoxin, Peruvosid, Proscillaridin = Digoxin, Ouabain; für das Meeschweinchen: Proscillaridin, Peruvosid = Digitoxin, Ouabain, Digoxin. 3. Die Bindung von Digitoxin im Darmgewebe ist bei Ratte und Meerschweinchen am größten. Das Verhältnis der Glykosid-Gehalte pro g Gewebe und pro ml Durchströmungsflüssigkeit betrug bei der Ratte für Digitoxin 3,3, für Ouabain 0,18, für Digoxin 0,6, für Peruvosid 1,1 und für Proscillaridin 1,2; beim Meerschweinchen für Digitoxin 4,2, für Ouabain 0,8, für Digoxin 0,16, für Peruvosid 0,9 und für Proscillaridin 1,4. 4. Auch in vivo, an abgebundenen Jejunumschlingen nimmt bei Ratten die resorbierte Menge proportional mit dem Angebot zu. Die Retention hängt vor allem von der mit der Galle ausgeschiedene Menge ab. 5. Es ergab sich kein Anhaltspunkt dafür, daß bei der Resorption der Glykoside ein Prozeß mit begrenzter Kapazität limitierend wird.
    Notes: Summary 1. Penetration and binding of tritiated ouabain, digitoxin, digoxin, peruvosid and proscillaridin were studied on isolated segments of the small intestine of rats and guinea pigs in vitro. 2. Penetration of glycosides through the intestinal wall is proportional to concentration. In rat intestine the penetration rate follows the order: digitoxin, peruvosid, proscillaridin = digoxin, ouabain; in guinea pig intestine: proscillaridin peruvosid = digitoxin, ouabain, digoxin. 3. In intestinal tissue of rats as well as of guinea pigs binding of digitoxin is highest. The relation of the glycoside content per g intestine to the content per ml perfusion fluid in the rat is 3.3 for digitoxin, 0.18 for ouabain, 0.6 for digoxin, 1.1 for peruvosid and 1.2 for proscillaridin; in the guinea pig 4.2 for digitoxin, 0.8 for ouabain, 0.16 for digoxin, 0.9 for peruvosid and 1.4 for proscillaridin. 4. Also in vivo the absorption of glycosides in tied loops of rat intestine is proportional to the amount offered. The retention of glycosides depends mainly on the excretion via the bile. 5. There is no indication that the absorption of glycosides depends on a process of limited capacity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 306 (1969), S. 219-226 
    ISSN: 1432-2013
    Keywords: (Na+K+)-ATPase ; (Mg++)-ATPase ; Rat ; Nephron ; Quantitative Histochemistry ; (Na+K+)-ATPase ; (Mg++)-ATPase ; Ratte ; Nephron ; Quantitative Histochemie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 17 male Wistar rats in antidiuresis 10 different nephron segments and arteries are identified with the aid of Lowry's technique, dissected and total-and (Mg++)-adenosintriphosphatase (=ATPase) determined. (Na+K+)-activated ATPase in the distal tubule is four to five times (max. eight times) more active than in the proximal segment. This difference of activity may speak for a high pump mechanism mediated by the way of a (Na+K+)-activated enzyme system in the distal nephron and for a partially passive reabsorption of sodium from the proximal convolution.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 16 (1969), S. 139-146 
    ISSN: 1432-2072
    Keywords: Metrazol ; Memory ; Discrimination Learning ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the first experiment rats were trained in black-white discrimination, then injected with 7.5, 10.0, or 15.0 mg/kg of pentylenetetrazol (Metrazol) or saline. Injections were given immediately or 15 min following training. The animals were retested 24 hours later. Improved performance was observed for drug groups, but the extent of improvement was a joint function of the amount of drug and the time at which it was given. Animals given 10 mg/kg showed greater retention when injection was delayed. In a second experiment animals were given spaced trials in a position discrimination task, extending over a period of several days. Following each day's, session, animals were injected with pentylenetetrazol or saline at intervals of 0, 5 or 10 min. A maximum facilitation effect was obtained at the 10-min interval.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 212 (1969), S. 243-253 
    ISSN: 1433-8491
    Keywords: 3-Acetylpyridine ; Cortical and Subcortical Leads ; Rat ; 3-Acetylpyridin ; Corticale und subcorticale Ableitungen ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ausgehend von zahlreichen neurochemischen und neuropathologischen Veröffentlichungen über die 3-Acetylpyridin (3-AP)-Vergiftung der Ratte wurde die bioelektrische Aktivität im Cortex und in subcorticalen Gebieten bei 15 3-AP-vergifteten Ratten studiert. Bei den künstlich beatmeten Tieren wurden mit Hilfe eines stereotaktischen Gerätes rostfreie Stahlelektroden im Hippocampus, Mandelkern, in der Formatio reticularis, im N. septi lateralis und N. caudatus sowie Silberelektroden im Cortex implantiert. Während der akuten 3-AP-Vergiftung konnten weder corticale noch subcorticale bioelektrische Veränderungen beobachtet werden. Vor und während der 3-AP-Vergiftung wurde die Formatio reticularis und der N. caudatus gereizt. Auch hierbei ergaben sich keine Unterschiede. Am Ende der Versuche wurde Cardiazol i.p. injiziert und regelmäßig eine diffuse Krampfaktivität provoziert. Die Befunde werden mit den elektrophysiologischen, neuropathologischen, neurologischen und neurochemischen Beobachtungen anderer Autoren diskutiert mit dem Ergebnis, daß die sog. Rollkrämpfe nach 3-AP-Vergiftung wahrscheinlich in der Hauptsache auf Läsionen der unteren Oliven zurückgeführt werden müssen.
    Notes: Summary Numerous neurochemical and neuropathologioal experimental studies concerning the 3-acetylpyridine (3-AP) poisoning of the rat have been previously published. In this paper the results of experiments on the bioelectrical activity in the cortex and in subcortical areas are presented on 15 rats poisoned with 3-AP. Stainless steel electrodes were implanted stereotactically in the hippocampus, nucleus amygdalae, formatio reticularis, nucleus septi lateralis and nucleus caudatus, and silver electrodes on the cortex of the artificially respirated animals. During the acute 3-AP poisoning neither cortical nor subcortical bioelectrical changes could be observed. The effect of stimulation on the formatio reticularis and the nucleus caudatus was not altered by the 3-AP intoxication. At the end of the experiments metrazol was injected intraperitoneally and in all cases diffuse convulsive discharges could be evoked. The findings are discussed and compared with the observations of other authors. The findings are comparible with the hypothesis that the so called “Rollkrämpfe” after 3-AP poisoning are caused by lesions in the oliva inferior.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969) 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 1-2 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 3-28 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Finite element methods can be formulated from the variational principles in solid mechanics by relaxing the continuity requirements along the interelement boundaries. The combination of different variational principles and different boundary continuity conditions yields numerous types of approximate methods. This paper reviews and reinterprets the existing finite element methods and indicates other alternative schemes. Plate bending problems are used to compare the relative merits of the various methods.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 47-66 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Three methods for finding natural frequencies and modes of complex structures composed of beam elements are described and compared. The analysis is extended to include hysteretic damping for the determination of response and transmissibility without a modal analysis. Experimental comparison is given for the response of a simple engineering structure.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 29-45 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The theory, function generator routine and testing procedures are given for a six-node 18 degree of freedom triangular element. At corner nodes the variables are the displacement and the two slopes. At midside nodes the variables are the displacement, the slope normal to the side, and the rate of change of this along the side - i.e., the rate of torsion. Of two options, one divides the triangle into three and takes different quartic displacements in the three regions, and the other uses displacement functions with singularities at the vertices. According to a test which compares the energies of the two formulations by eigenvalues, the second is the better if the integration is accurate. The same test, together with others based on finite differences and on nodal values, etc. checks the correctness of the routine decisively.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 67-73 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Finite difference treatment of two-dimensional problems in elastostatics is usually based on the differential equations for the displacement vector or the Airy stress function, depending on whether boundary conditions are on displacement or stress. In either case, determination of stresses requires numerical differentiation and therefore use of a rather fine grid. Moreover, neither method is suited to the treatment of mixed boundary conditions. The alternative method developed in this paper uses the first derivatives of the displacement components at the grid points as basic variables and hence does not require numerical differentiation in the evaluation of stresses. Appropriate finite difference equations are established, and their use is discussed in connection with a specific example with known explicit solution.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969) 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 279-299 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: When calculating complex interconnected systems (electrical, power, water supply, gas systems, etc.) by digital computer, a number of common problems arise, connected both with the mathematically correct formulation of the problem under investigation, and with the algorithms of the solution, the programming of which makes it possible to reduce the computing time, the store capacity and the volume of input data required. The present article is devoted to the solution of these problems. The procedure is illustrated by formulating and manipulating the equations relating to complex interconnected mine ventilation networks.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 301-310 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Solution of plane elastic problems by piecewise linear approximation is outlined. This method is based upon Galerkin error distribution technique, which leads to simultaneous algebraic equations identical to those associated with the Finite Element Method. In addition, this method permits definition of the discretization error, which can be computed once the displacement components are known. Properties of the interpolation functions are discussed, and a sequence of internally compatible plane elastic elements is defined.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 311-331 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A review is given of some mathematical programming methods suitable for optimization of structures needing matrix methods for analysis. An application is presented for elastic flat grillages made of straight orthogonal beams normally loaded. Empirical relationships are used to relate beam section properties so that each beam element has only one design variable. Optimization results are obtained by methods of stress-ratio, linear programming-cutting plane and usable-feasible gradient directions. A comparison of the efficiency of these methods is given for the grillage designs which are shown to have non-convex stress constraints and numerous relative optima. Instances are given of non-fully stressed global optima and fully stressed designs which are not local optima for cases with only stress constraints. Discussions include locating the global optima for grillage designs and extensions of the methods presented to other structural design problems.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 379-394 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A completely numerical method for steady state linear viscoelastic stress analysis is presented by means of the finite element approach. Numerical representations of the measured viscoelastic constitutive relations are used. This method is developed to obtain steady state solutions to mixed boundary value problems in which the character of the boundary conditions at a point changes with time. Such problems cannot be handled by direct application of the correspondence theorem. A numerical example of viscoelastic sheet rolling is presented along with an experimental verification of the solution by photo-viscoelastic observations.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 351-378 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The application of non-linear programming methods for the optimum design of statically indeterminate structures is discussed, with special emphasis on the design of elastic grillages loaded laterally and in plane. Some features of SUMT (sequential unconstrained minimization technique) are demonstrated by means of numerous examples of varying complexity. The Variable Metric method of search is discussed and compared to Powell's Direct Method. It is shown that non-convex sets of design variables are often encountered in structural problems of the grillage type. SUMT may still be used, but the choice of starting value and initial response factor decisively influences the chance of finding the global optimum.It is demonstrated that a fully stressed design may not necessarily correspond to the minimum weight design. Optimum design of grillages which are simultaneously subjected to lateral and in-plane loads may be performed efficiently by means of non-linear programming.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 395-395 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 275-277 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 75-100 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The paper presents first a general formulation of the elasto-plastic matrix for evaluating stress increments from those of stresses for any yield surface with an associated flow rule. A new ‘initial stress’ computational process is proposed which is shown (1) to yield more rapid convergence than alternative approaches (2) to permit large load increments without violating the yield criteria and thus simply to establish lower bound solutions. Several solutions showing stress distribution, strain development and growth of plastic enclaves are given both for the von Mises and for Coulomb (Drucker) type yield surfaces. Load reversal and thermoplastic behaviour are dealt with.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 135-149 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The assumed stress distribution approach is used to derive the stiffness matrix of a plate-bending element of general polygonal shape having any number of nodes. The effect of assuming various numbers of unknown coefficients in the stress distributions is examined and the convergence properties of the resulting elements compared with others derived form assumed displacements.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 163-167 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Deformation functions which, in addition to satisfying the continuity conditions at nodes. Also satisfy. Approximately, the governing differential equation within the element allow system eigenvalues to be found more accurately, with a given number of elements, than is possible with previously published deformation functions. This is illustrated for the case of beams.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 169-175 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A numerical method for obtaining the Green's functions for Laplace's, Poisson's, and the transient heat diffusion equations is presented. The Green's functions thus obtained are then employed to rapidly obtain numerical solutions of the above equations by matrix multiplication, with subsequent considerable savings in machine time.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 151-162 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The direct Finite Element Analysis which was successfully employed in the solution of dynamic flexural traveling wave problems is extended herein to provide the transient behaviour of finite beams and plates in which shear deformation and rotatory inertia are considered. The particle and angular velocities are exponentially damped so that the static solutions for these problems are obtained with the same analysis which provided the dynamic and transient cases. Three special cases are chosen as examples. In the first, a sinusoidally varying shear force is applied at the tip of a cantilever beam. The resonant characteristics of this beam for both the undamped and damped cases are studied. In the second, a step shear loading is applied to a cantilever beam and its damped dynamic history is studied. Finally, a circular plate whose outer edge is simply supported is impacted at its inner edge by a step moment and its damped transient behaviour is determined. The idea of the methods is potentially applicable to dynamic problems in general.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 177-180 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The solution of the large numbers of non-linear algebraic equations occurring in analyses of non-linear structural systems using finite differences or finite elements is time consuming even for the fastest computers. This paper presents a method of solution based on a Taylor's expansion technique which is an aid in the solution of such systems of equations.Examples presented show that in the finite element analysis of moderately non-linear structural systems the technique provides sufficiently accurate solutions. For more non-linear systems the technique provides excellent starting values for the Newton-Raphson method.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 201-203 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 181-200 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Surface displacements at the end of a semi-infinite, circular cylinder due to an axisymmetric ring of forces on the end are examined. The solution which has been found may then be used to find surface displacements for general axisymmetric loadings by convolution. The solution, in tabular form, is given as corrections to the counter-part half-space solution.The method of solution involves a three step superposition process. First, the displacement due to a ring of forces on a half-space is found by using the Boussinesq solution. Then, the excess tractions on the half-space, over that of the cylinder, are removed. This is done in two parts. The problem of an infinite cylinder with linearly varying pressure and shear over a short length of the lateral surface is solved by using Fourier integrals. This is used for the removal of the pressure and shear on the lateral surface of the cylinder by convolution. Next, the stresses at the mid-section of the infinite cylinder are removed. This is done by finding a set of boundary conditions for the end which yields zero tractions on the lateral surface. Then a series of these boundary conditions is used to approximate the tractions which must be removed.With the solution thus obtained, two sample problems are shown: 1. an elastic cylinder in contact with a half-space; 2. a rigid punch in contact with an elastic cylinder.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969) 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 205-221 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a general theory of finite elements. The concept of finite elements is cast in a general topological framework valid for spaces of finite dimension. It is shown that the idea of finite element models can be developed in higher-dimensional spaces, independent of specific co-ordinate systems, for any type of continuous abstract function defined on the space. Generalizations of the familiar Lagrange and Hermite interpolation functions are presented as well as a general statement of the notion of generalized variables and conjugate fields. It is also shown that admissible finite elements can be developed for non-Euclidean spaces of finite dimension. Topological properties of finite element models are examined in Part I of the paper. Part II is devoted to certain applications.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 224-224 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 247-259 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In Part I of the this paper, topological properties of finite element models of functions defined on spaces of finite dimension were examined. In this part, a number of applications of the general theory are presented. These include the generation of finite element models in the time domain and certain problems in wave propagation, kinetic theory of gases, non-linear partial differential equations, non-linear continuum mechanics, and fluid dynamics.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 225-245 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A method is presented based on matrix algebra for the dynamic analysis of a mixed rotating and non-rotating vibration system. Such systems occur in practice when turbo-alternator sets are mounted on flexible steel foundations.The mathematical model considered consists of a rotating non-uniform, bi-symmetric shaft connected via three or more flexible-film bearings to a flexible structure throughout which mass is distributed. The shaft, which is assumed to rotate at constant speed, is heavy, flexible and carries several rigid axi-symmetric discs. Viscous damping is assumed to act in all parts of the system and gravitational effects are ignored.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 261-274 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A presentation is made of a rectangular plate bending element, the use of which corresponds to the finite difference method. The element stiffness matrix is arrived at by approximation of the strain energy of the element by suitably selected finite difference expressions which contain not only values in respect of the deflection, but also values of its first derivatives. On the basis of the connection found between the two methods, some changes are suggested in the finite difference method, which involve a more realistic way of considering the detailed distribution of the loading. The effect of these modifications is illustrated in two applications.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 101-122 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The derivation of the stiffness matrix for a refined, fully compatible triangular plate bending finite element is presented. The Kirchhoff plate bending theory is assumed. Six parameters or degrees of freedom are introduced at each of the three corner nodes resulting in an 18 degree of freedom element. This refined element is found to give better results for displacements and particularly for internal moments than any plate bending element, regardless of shape, previously reported in the literature.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 123-133 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The large deflection problem of a rectangular plate is analysed by using the finite element method and employing the iteration technique. In the present study, the stiffness matrix of a rectangular plate element for bending proposed by Greene is employed, and results of numerical examples duly justifies applicability of the present method.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969) 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 1 (1969), S. 333-349 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The paper presents a method for reducing the size of a vibration analysis by generating an inertia matrix referred to a limited set of ‘master’ vibrational freedoms. In designing a computer program to perform this mass condensation process, the emphasis has been on providing a two way interface between structural analysis and vibration analysis programs. The transformation from the full set of degrees of freedom to the master set makes extensive vibration calculations economically feasible giving solutions in terms of the amplitudes of the master freedoms. However, by reversing the transformation after completion of a vibration analysis, it is possible to restore the full set of freedoms, allowing automatic plotting of mode shapes in full detail, and re-entry to the structural analysis program for the purpose of computing dynamic stresses.A worked example is given. This is a realistic machine tool structure rather than the simple plates or beams which are usually used for illustration purposes. Natural frequencies and mode shapes, calculated with various degrees of condensation, are compared with those obtained by using all possible freedoms. A comparison is also made with an intuitive selection of ‘lumped masses’.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1432-1106
    Keywords: Hippocampal Lesions ; Rat ; Fixed Ratio ; Acquisition ; Extinction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats with bilateral anterior and posterior hippocampal lesions (APH), anterior hippocampal lesions (AH), and controls were trained on CRF for water, and then switched to FR-20. Both hippocampal groups adapted more readily than controls to the FR-20 schedule and maintained significantly higher rates for 45 days. There were no significant differences on FR-20 between the lesion groups. Following FR-20, the rates of all groups were equalized by training on FR-30. During subsequent extinction, the APH group made significantly more responses than both the AH and control groups, while AH and control groups were indistinguishable. The acquisition results were interpreted as indicating increased emotional reactivity to delay of anticipated reward in both hippocampally lesioned groups. The extinction results suggested that APH, but not AH, lesions also result in increased perseveration.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 1432-1106
    Keywords: Synapse ; Granular vesicles ; Noradrenaline ; Nialamid ; Ventromedial hypothalamic nucleus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of ventromedial hypothalamic nucleus was studied in the rat with the electron microscope under circumstances of elevated brain monoamine level following treatment with a monoamine oxidase inhibitor Nialamid. The number of granular vesicles (size in diameter 450–1100 Å) in synaptic terminals increased after Nialamid treatment significantly, while their size did not change; the number of agranular vesicles remained unchanged. The time courses of the increase of granular vesicles and elevation of brain noradrenaline content were approximately parallel. It is inferred that the granular vesicles of size 450 to 1100 Å may possibly be the storage sites of noradrenaline.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 146 (1968), S. 275-283 
    ISSN: 1591-9528
    Keywords: Anti-lymphocyte serum ; 51Cr-labelled lymphocytes ; Rat ; Antilymphocytenserum ; 51Cr-markierte Lymphocyten ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. 48 Ratten wurden in Äthernarkose 107 51Cr-markierte Lymphocyten suspendiert in Hankscher Lösung und Heparin in die V. femoralis injiziert. Ein Teil der Tiere bekam gleichzeitig Antilymphocytenserum. Dabei wurde festgestellt, daß der normale Abbau51Cr-markierter Lymphocyten in einer bestimmten zeitlichen Reihenfolge in Lunge, Leber, Milz und peripheren Lymphknoten vonstatten geht und51Cr durch die Niere ausgeschieden wird. Ein Wiederansteigen der Radioaktivität in den erwähnten Organen nach 18–22 Tagen wird mit einem Reutilisationseffekt erklärt. 2. Durch Kaninchen-Anti-Ratten-Lymphocytenserum (ALS) wird diese Verteilung beschleunigt und verändert. In der Lunge findet man eine sehr starke, in der Milz dagegen fast gar keine Anhäufung51Cr-markierter Lymphocyten, was auf eine Schädigung dieses Organs durch ALS hinweisen könnte.
    Notes: Summary 1. 107 51Chromium-labelled lymphocytes have been injected into the femoral vein of 48 rats in aetheranaesthesia. The lymphocytes were suspended in heparinized Hank's solution. 20 animals were treated with antilymphocyte serum at the same time. The normal distribution of51Cr-labelled lymphocytes was found to take place in lung, liver, spleen and peripheral lymphnode in a certain chronological order.51Chromium is eliminated by the kidney. After a period of 18–22 days an increase of radioactivity is found in organs mentioned above which is to be explained by reutilisation of radioactivity. 2. This normal distribution is changed by rabbit-anti-rat-lymphocyte serum. In the lung it is found more of51Cr-labelled lymphocytes in the spleen less than in control animals. These findings suggest a damaging effect induced by antilymphocyte serum.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 261 (1968), S. 314-328 
    ISSN: 1432-1912
    Keywords: Rat ; Gut ; Absorption ; Free Bile Acids ; Conjugated Bile Acids ; Ratte ; Darm ; Resorption ; freie Gallensäure ; konjugierte Gallensäuren
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Zur Klärung der Frage, ob für die Anreicherung freier Gallensäuren in Coecum und Colon eine unterschiedliche Resorption freier und konjugierter Gallensäuren im Dünndarm mitverantwortlich ist, wurden in vitro an nicht durchbluteten, isoliert durchströmten Dünndarmsegmenten der Ratte ihr Durchtritt und ihre Bindung untersucht. Die Ergebnisse wurden mit denjenigen verglichen, die in vivo an durchbluteten, abgebundenen Ileumschlingen bei Ratten in situ gewonnen wurden. Folgende Gallensäuren standen zur Verfügung: Cholsäure, deren Taurin- und Glycin-Konjugat; Desoxycholsäure sowie deren Taurin- und Glycin-Konjugat. 2. Die in vitro-Versuche ergaben, daß konjugierte Gallensäuren, gemessen an der Konzentration im Resorbat, in größerem Umfange als freie durch die Mucosa treten. Je polarer die Gallensäure, desto größer die Durchtrittsrate. Beim Durchtritt werden weder freie Gallensäuren mit Taurin bzw. Glycin konjugiert, noch werden Gallensäure-Konjugate in nennenswertem Umfange hydrolytisch gespalten. Der durch die Darmwand gebundene Anteil freier Gallensäuren ist größer als der konjugierter. 3. In vivo erfolgt die Resorption aus Ileumschlingen so schnell, daß innerhalb von 15 min von allen Gallensäuren gleichviel resorbiert wird. Das Ausmaß der Bindung der Gallensäuren in der Darmwand ist unterschiedlich. Von Desoxycholsäure wird auch in vivo doppelt soviel gebunden wie von Glykocholsäure. 4. Das Ergebnis der Versuche besagt, daß in vivo eine geringere Resorption für die Anreicherung freier Gallensäuren im Dickdarm keine Rolle spielt. Die Unterschiede im Durchtritt freier und konjugierter Gallensäuren in vitro sind methodisch bedingt.
    Notes: Summary 1. In order to elucidate the question whether the coecal and colonic accumulation of free bile acids is caused by different absorption of free and conjugated bile acids in the small intestine, their penetration and their binding were studied in vitro in isolated rat gut segments. The results were compared with those in vivo obtained with tied loops in situ. The following bile acids were available: cholanic acid, its taurine and glycine conjugates; deoxycholic acid and both its conjugates. 2. The experiments in vitro showed that relative to the concentration in the absorbed fluid, the penetration rate of conjugated bile acids is higher than that of free bile acids. The more polar a bile acid is the greater is the penetration rate. During penetration neither free bile acids are conjugated with taurine or glycine nor conjugated bile acids are hydrolysed. 3. In vivo absorption in ileal loops is so rapid that within 15 min the absorption rate is nearly the same for all bile acids. The amounts of bile acids bound by the tissue vary. In vivo, as in vitro, twice as much deoxycholic acid is bound as glycocholic acid. 4. The results show that in vivo a lesser absorption is of no significance for the accumulation of free bile acids in the colon. The difference in the absorption of free and conjugated bile acids in vitro is caused by the method.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 259 (1968), S. 413-418 
    ISSN: 1432-1912
    Keywords: Cyproterone Acetate ; Hexobarbital Narcosis ; Rat ; Testosterone ; Enzyme Induction ; Cyproteronacetat ; Hexobarbitalnarkose ; Ratte ; Testosteron ; Fermentinduktion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An geschlechtsreifen Ratten wurde der Einfluß des Antiandrogens Cyproteronacetat auf die Hexobarbitalnarkose bei Ratten in Abhängigkeit vom Hormonstatus geprüft. Cyproteronacetat entfaltet in diesem Versuchsmodell nicht seine sonst bekannte spezifische Hemmwirkung gegenüber endogenem und injiziertem Testosteron. Die Vorbehandlung mit Cyproteronacetat führt zu einer Steigerung der mikrosomalen Fermentaktivität in der Leber und damit wahrscheinlich zu einem schnelleren Abbau von Hexobarbital. Die Folge ist eine erhebliche Narkosedauerverkürzung durch diese Verbindung.
    Notes: Summary The influence of the antiandrogen Cyproterone acetate on Hexobarbital narcosis in relation to the hormonal state was investigated in adult rats. In this test model Cyproterone acetate failed to exert its wellknown specific inhibitory action on endogeneous and injected testosterone. Pretreatment with Cyproterone acetate led to enhanced microsomal enzyme activity in the liver and thus probably to a more rapid metabolism of Hexobarbital. The result of this is a significant shortening of the duration of narcosis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 261 (1968), S. 225-238 
    ISSN: 1432-1912
    Keywords: Iron Deficiency ; Iron Absorption ; Iron Complexes ; Rat ; Eisenmangel ; Eisen-Resorption ; Eisenkomplexe ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Die Retention von freiem und komplexgebundenem 59Fe-Eisen wurde 6 Tage nach Verabreichung mit der Schlundsonde bei normalen und anämischen Ratten in einer Ganztiermeßanlage bestimmt. 2. Anämische Ratten nahmen fünfmal mehr Eisen auf als normale Tiere, wenn ionisiertes Eisen angeboten wurde. Alle geprüften Komplexbildner vermindern die gesteigerte Eisen-Retention anämischer Ratten. Bezogen auf die Werte der anämischen Gruppe (=100%) wurde die Retention durch EDTA um 87%, durch Citronensäure um 40%, durch Ascorbinsäure um 32% und durch Nicotinhydroxamsäure um 31% herabgesetzt. 3. In Gegenwart von Komplexbildnern ist die Eisen-Retention anämischer Tiere bei Citronensäure 8,7, von EDTA 6,3, von Nicotinhydroxamsäure 3,7 und von Ascorbinsäure 2,7 mal höher als bei normalen.
    Notes: Summary 1. In normal and anemic rats, the retention of free and complex-bound 59Fe-iron was measured with a whole body counter 6 days after its oral administration. 2. If the iron is administered in the ionic form to iron-deficient rats they show a retention of iron 5 times greater than that of normal animals. The increased iron retention of anemic rats is diminished by all complexing agents tested. EDTA reduced it by 87%, citric acid by 40%, ascorbic acid by 32% and nicotine hydroxamic acid by 31%. 3. When the iron is combined with citric acid its retention by iron-deficient rats was 8.7 times increased in comparison to normal rats, with EDTA 6.3 times, with nicotine hydroxamic acid 3.7 and with ascorbic acid 2.7 times.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 259 (1968), S. 260-265 
    ISSN: 1432-1912
    Keywords: Intestine ; Rat ; Phenol red ; Absorption ; Active transport ; Darm ; Ratte ; Phenolrot ; Resorption ; Aktiver Transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Phenolrot wird aus dem Jejunum der Ratte im wesentlichen passiv durch Diffusion resorbiert. Ein kleiner Anteil der resorbierten Menge folgt jedoch Charakteristica eines aktiven Prozesses. Die Resorption dieses Anteils wird durch p-Aminohippursäure (PAH) unterdrückt. In vitro baut Darmgewebe einen Teil von verabreichtem Phenolrot um, so daß es sich dem photometrischen Nachweis entzieht. Diese Reaktion wird durch PAH nicht beeinflußt. Aus dem Verhalten von PAH wird geschlossen, daß es sich bei der aktiven Elimination von Phenolrot aus dem Darm in vivo nicht um Stoffwechsel, sondern um aktiven Transport handelt, der Ähnlichkeit mit den Säuretransportmechanismen in anderen Organen zeigt. Die Phenolrotresorption ist unabhängig von der Art der Kationen in der zur Resorption angebotenen Phenolrotlösung, soweit es sich um Na-, K- oder Na-K-Ionengemische handelt. Auch wenn in der zur Resorption verabreichten Lösung alle Na- und K-Ionen durch Li-Ionen ersetzt werden, bleibt die Phenolrotresorption ohne signifikante Änderung.
    Notes: Summary Phenol red is absorbed from the jejunum of the rat mainly by diffusion. A small proportion of the amount administered, however, disappears from the gut in a way that suggests an active process. The disappearance of this part is inhibited by p-aminohippurate (PAH). In vitro, phenol red is partly metabolized by jejunal tissue. PAH has no effect on this metabolism. From the interaction of PAH it is concluded that the active elimination of phenol red from the jejunum in vivo is due to absorption by active transport and not to metabolism. This process is similar to the active transport of organic acids known in other organs in that it is inhibited by PAH. Absorption of phenol red is not influenced by the kind of cations present in the solution, as far as sodium, potassium or mixtures of both ions are concerned. Substitution of lithium for sodium and potassium does not result in significant changes in the absorption of phenol red.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 304 (1968), S. 315-321 
    ISSN: 1432-2013
    Keywords: Lung ; Alveolar Surface Tension ; Aerobic Metabolism ; Breathing Mechanics ; Rat ; Lunge ; Alveoläre Oberflächenspannung ; Oxydativer Stoffwechsel ; Atemmechanik ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Beatmet man isolierte Rattenlungen mit Drucken von 0–25 cm H2O (Überbeatmung), so zeigen sich im statischen Druck-Volumen-Diagramm Veränderungen, die auf eine Zunahme der Oberflächenspannung in den Lungenalveolen hinweisen. Läßt man die Lungen im Anschluß an die Beatmung 30 min im geblähten Zustand, so wiest das Verhalten despV-Diagramms auf ein Wiederabsinken der alveolären Oberflächenspannung hin, wenn die Versuche bei 37°C vorgenommen wurden, während eine derartige Änderung bei 20–24°C nur angedeutet nachzuweisen ist. 2. Wird der oxydative stoffwechsel durch Beatmung der Lunge mit N2 oder Vergiftung mit KCN ausgeschaltet, so zeigen sich prinzipiell sowohl während der Beatmung als auch in der Restitutionsphase die gleichen Verhältnisse, nur daß unter anoxischen Bedingungen die alveoläre Oberflächenspannung während der Beatmung noch etwas stärker ansteigt. Danach spielt der oxydative Stoffwechsel für die beobachteten Erscheinungen eine untergeordnete Rolle. 3. Wahrscheinlich wird durch die Überbeatmung der Oberflächenfilm in den Lungenalveolen mechanisch geschädigt, wobei ein Teil des oberflächenaktiven Materials inaktiviert wird. Eine Restitution könnte durch Wiederspreitung des inaktivierten Materials oder durch Übertreten von LAS aus den Alveolarzellen an die Alveolaroberfläche erfolgen.
    Notes: Summary The effect of ventilation on the lung alveolar lining layer has been demonstrated by analysis of pressure-volume diagrams. Ventilation of isolated rat lungs at intrapulmonary pressures of 0–25 cm H2O caused an increase of surface forces in the lungs. After ventilation was stopped the lungs were kept inflated at intrapulmonary pressures of 25 cm H2O up to 60 min. Subsequent analysis of the pressure-volume diagrams indicated a decrease of surface forces at 37°C while at 20–24°C only little recovery occurred. The influence of ventilation with N2 or poisoning with KCN on aerobic cell metabolism was investigated. The increase of surface forces was only slightly more pronounced by anoxia during lung-ventilation than in the above experiments. Aerobic cell metabolism, therefore, did not play an important role in our experiments. It is very likely that the decrease of surface activity following ventilation was caused by mechanical changes of the alveolar lining layer. We believe that, to some extent, the lung alveolar surfactant was inactivated. Recovery can be explained by new spreading of inactivated materials or by passage of lung alveolar surfactant from the alveolar cells to the alveolar surface.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 1432-2072
    Keywords: Operant Behavior ; Methylphenidate ; Pentobarbital ; Reserpine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three rats, deprived of water, were given separate injections of methylphenidate and pentobarbital after each had received extensive training on a DRL schedule of reinforcement, modified by the inclusion of a limited-hold. Methylphenidate (2.5, 5.0, and 10.0 mg/kg) increased response rates at each of these dosages; pentobarbital increased response rates at dosages of 2.5 mg/kg and 5 mg/kg but had little effect on overall response rate at 10 mg/kg though, at this dose, performance was characterized by periods of rapid responding alternating with periods of inactivity. The rate-increasing effects of the two drugs were found to be qualitatively different. Several mixtures of the two drugs induced rate increases greater than those found when each drug was given separately. However, pentobarbital (10 mg/kg) reduced the rate-increasing effects of methylphenidate obtained when the latter was given alone at a dosage of 10 mg/kg. Chronic pretreatment with reserpine (0.3 mg/kg for 12 days), given to two animals, progressively reduced rate of responding. Methylphenidate antagonized the effects of reserpine as an increasing function of dosage but the resulting pattern of behavior more closely resembled the effects of methylphenidate given alone than performance recorded in the absence of any drug treatment.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Clinical and experimental medicine 145 (1968), S. 260-265 
    ISSN: 1591-9528
    Keywords: Renal puncture ; Renal needle biopsy ; Rat ; Nierenpunktion ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 90 Ratten wurden insgesamt 266 Nierenpunktionen durchgeführt. Selbst Serienbiopsien (bis zu acht Eingriffen pro Tier bzw. bis fünf Punktionen pro Niere) mit Intervallen von wenigen Tagen wurden gut vertragen. Drei Methoden wurden versucht: percutane Blindbiopsie, Punktion unter Sicht von dorsal (extraperitoneal) bzw. von ventral (transperitoneal). Bei Berücksichtigung der wichtigsten Momente (Ergiebigkeit des Punktates, Schwierigkeit des Eingriffes — auch bei nachfolgenden Punktionen —, lokale Folgen an der Niere und Umgebung) hat sich dastransperitoneale Vorgehen als dieMethode der Wahl erwiesen und ausgezeichnete Ergebnisse geliefert. Die Nierenpunktion der Ratte kann besonders zum Studium des Verlaufes experimenteller Nierenkrankheiten mit morphologischen Methoden empfohlen werden.
    Notes: Summary In 90 rats 266 renal puncture biopsies were performed. Even serial biopsies (up to eight per animal or up to five punctures per kidney, respectively) were tolerated very well. Three methods were attempted: Percutaneous blind biopsy, puncture under direct vision by a dorsal (extraperitoneal) approach and by a ventral (transperitoneal) one. Considering the most important factors (e.g. amount of the puncture sample, difficulty of the procedure even in subsequent punctures, local damage to the kidney) the transperitoneal approach has proved to be the method of choice and excellent results were obtained. Renal puncture of rats are especially suitable for studying diseases of the kidney by morphological methods.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 257 (1967), S. 409-419 
    ISSN: 1432-1912
    Keywords: Chelating agents ; Iron storage disease ; Rat ; Chelatbildner ; Eisenspeicherkrankheit ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurde der Einfluß folgender Chelatbildner: 1. Diäthylentriaminpentaessigsäure (DTPA), 2. 2,2′-Bis[di(carboxymethyl)amino]diäthyläther (BADÄ), 3. 2-(β-Aminoäthoxy)cyclohexylamintetraessigsäure (ACATA) und 4. Desferrioxamin B (DF) auf die Fe-Ausscheidung mit dem Urin von Ratten geprüft. Sowohl bei Kontrolltieren als auch bei experimentell induzierter Fe-Speicherkrankheit nimmt die Wirksamkeit in der Reihenfolge DTPA 〈 BADÄ ≃ DF 〈 ACATA zu. Die akute LD 50 bei der Maus beträgt 2,4 mM DF·kg−1 und 12,7 mM ACATA·kg−1.
    Notes: Summary The influence of 1. diethylenetriaminepentaacetic acid (DTPA), 2. 2,2′-bis-[di(carboxymethyl)-amino]diethyl ether (BADE), 3. 2-(β-aminoethoxy)-cyclohexylaminetetraacetic acid (ACATA), and 4. desferrioxamine B (DF) on the urinary iron excretion was studied in rats. In controls as well as in animals with experimental hemochromatosis the effectivity increases in the following order: DTPA 〈 BADE ≃ DF 〈 ACATA. The acute LD50 of DF is 2.4 mM×kg−1 and of ACATA 12.7 mM×kg−1 in mice.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 1 (1966), S. 299-305 
    ISSN: 1432-1106
    Keywords: Prolongation of dioestrus ; Brain-stem ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Diencephalic and mesencephalic lesions in albino rats elicited a disturbance of the vaginal oestrous cycle characterized by “pseudopregnancy-like” prolongation of dioestrus; occasionally decidual responses could be elicited by uterine traumatization. Oestrogen administration on the day before traumatization failed to enhance significantly the frequency of decidual responses in rats with diencephalic lesions, but succeeded in doing so in rats with mesencephalic lesions. It is assumed that the lesions destroy partially the mesencephalo-hypothalamic afferent system containing nerve fibres stimulating the hypothalamic cells producing the luteotrophin (prolactin) inhibiting factor.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 2 (1966), S. 168-175 
    ISSN: 1432-1106
    Keywords: Spreading depression ; Pupilla ; Thalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Spreading depression elicited in the thalamus of albino rats anesthetized with Dial by microinjection of 0.2–1.0 μl 25% KCl is accompanied by a maximal pupillary dilatation of the paralytic type. The mydriasis starts immediately after KCl application, culminates about 90 sec later and then slowly subsides with a half time of about 5 min. Although with lateralized KCl application thalamic spreading depression reaches the ipsilateral lateral geniculate body approximately 1 min earlier than the contralateral one, the pupillary reactions are strictly synchronous in both eyes. Participation of the sympathetic fibres was ruled out by the observation that thalamic spreading depression evokes the same mydriasis in the “encéphale isolé” rats. Cortical spreading depression, on the contrary, elicits only slight and shortlasting mydriasis. Comparison of the spatial march of spreading depression through the thalamus with the time course of the pupillary reaction indicates that the maximum mydriasis is probably caused by direct invasion of the Edinger-Westphal nucleus by the spreading depression process.
    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...